diff --git a/src/main/benchmarks/README.org b/src/main/benchmarks/README.org
index d573ad0..d9b00c1 100644
--- a/src/main/benchmarks/README.org
+++ b/src/main/benchmarks/README.org
@@ -224,6 +224,7 @@ The word lists ~colors.txt~ and ~monsters.txt~ takes the most time by far (aroun
    generateCrossword 3
  #+END_SRC
 
+
 ** Configure the algorithm
 
 *** Addition
@@ -245,7 +246,6 @@ The word lists ~colors.txt~ and ~monsters.txt~ takes the most time by far (aroun
 * Solve
 ** Create the solver
 *** Cryptator
-**** Simple Precision
 
 #+BEGIN_SRC sh :tangle solver.sh
   JAR=cryptator-0.6.0-SNAPSHOT-with-dependencies.jar
diff --git a/src/main/cryptarithms/long-multiplications/samples.db.txt b/src/main/cryptarithms/long-multiplications/samples.db.txt
new file mode 100644
index 0000000..ac7b52a
--- /dev/null
+++ b/src/main/cryptarithms/long-multiplications/samples.db.txt
@@ -0,0 +1,6 @@
+in * gag = vain && in * '1' + kan * '10' + in * '100' = vain && in * g = in && in * a = kan && in * g = in
+in * gag = vain && in * '1' + km * '10' + in * '100' = vain && in * g = in && in * a = km && in * g = in
+in * go = kan && in * '1' + km * '10' = kan && in * g = km && in * o = in
+in * ive = olim && km * '1' + go * '10' + in * '100' = olim && in * i = in && in * v = go && in * e = km
+km * km = kan && in * '1' + km * '10' = kan && km * k = km && km * m = in
+surs * cc = relus && surs * '1' + surs * '10' = relus && surs * c = surs && surs * c = surs
diff --git a/src/main/java/cryptator/config/CryptaLogConfig.java b/src/main/java/cryptator/config/CryptaLogConfig.java
index 371a456..978c603 100644
--- a/src/main/java/cryptator/config/CryptaLogConfig.java
+++ b/src/main/java/cryptator/config/CryptaLogConfig.java
@@ -21,7 +21,7 @@ public final Verbosity getVerbosity() {
         return verbosity;
     }
 
-    public final void setVerbosity(Verbosity verbosity) {
+    public final void setVerbosity(final Verbosity verbosity) {
         this.verbosity = verbosity;
     }
 
diff --git a/src/main/java/cryptator/config/CryptagenConfig.java b/src/main/java/cryptator/config/CryptagenConfig.java
index e861f75..373401f 100644
--- a/src/main/java/cryptator/config/CryptagenConfig.java
+++ b/src/main/java/cryptator/config/CryptagenConfig.java
@@ -54,7 +54,7 @@ public final int getGridSize() {
         return gridSize;
     }
 
-    public final void setGridSize(int gridSize) {
+    public final void setGridSize(final int gridSize) {
         this.gridSize = gridSize;
     }
 
@@ -98,7 +98,7 @@ public final boolean isMultModel() {
         return multModel;
     }
 
-    public final void setMultModel(boolean multModel) {
+    public final void setMultModel(final boolean multModel) {
         this.multModel = multModel;
     }
 
@@ -106,7 +106,7 @@ public final boolean isLongMultModel() {
         return longMultModel;
     }
 
-    public final void setLongMultModel(boolean longMultModel) {
+    public final void setLongMultModel(final boolean longMultModel) {
         this.longMultModel = longMultModel;
     }
 
diff --git a/src/main/java/cryptator/gen/AbstractCryptaGenModel.java b/src/main/java/cryptator/gen/AbstractCryptaGenModel.java
index f7af6df..1272cc9 100644
--- a/src/main/java/cryptator/gen/AbstractCryptaGenModel.java
+++ b/src/main/java/cryptator/gen/AbstractCryptaGenModel.java
@@ -37,6 +37,13 @@ public abstract class AbstractCryptaGenModel implements ICryptaGenModel {
     /** The maximum length of a present word. */
     protected final IntVar maxLength;
 
+    /**
+     * Instantiates a new model for the generation.
+     *
+     * @param model  the model
+     * @param words  the words
+     * @param prefix the prefix for variable names
+     */
     protected AbstractCryptaGenModel(final Model model, final String[] words, final String prefix) {
         super();
         this.model = model;
@@ -46,6 +53,11 @@ protected AbstractCryptaGenModel(final Model model, final String[] words, final
         this.maxLength = model.intVar(prefix + "maxLength", 0, AbstractCryptaGenModel.getMaxLength(words), false);
     }
 
+    /**
+     * Gets the model.
+     *
+     * @return the model
+     */
     @Override
     public final Model getModel() {
         return model;
@@ -87,14 +99,26 @@ private static BoolVar[] buildWordVars(final Model model, final String[] words,
         return vars;
     }
 
+    /**
+     * Post constraints for the presence of words.
+     */
     protected abstract void postWordConstraints();
 
+    /**
+     * Post word count constraint.
+     */
     protected void postWordCountConstraint() {
         model.sum(vwords, "=", wordCount).post();
     }
 
+    /**
+     * Post the constraints that set the maximum length.
+     */
     protected abstract void postMaxLengthConstraints();
 
+    /**
+     * Builds the model.
+     */
     @Override
     public void buildModel() {
         postWordConstraints();
@@ -115,6 +139,11 @@ public void postWordCountConstraints(final int min, final int max) {
         }
     }
 
+    /**
+     * Post a constraint that set the number of words.
+     *
+     * @param val the number of words
+     */
     public void postWordCountConstraints(final int val) {
         wordCount.eq(val).post();
     }
@@ -124,18 +153,44 @@ public String toString() {
         return GenerateUtil.recordString(this, " ");
     }
 
+    /**
+     * Gets the maximum length of the words.
+     *
+     * @param words the words
+     * @return the maximum length
+     */
     public static final int getMaxLength(final String[] words) {
         return Arrays.stream(words).mapToInt(String::length).max().orElse(0);
     }
 
+    /**
+     * Gets the sum of the word lengths.
+     *
+     * @param words the words
+     * @return the sum of the lengths
+     */
     public static final int getSumLength(final String[] words) {
         return Arrays.stream(words).mapToInt(String::length).reduce(0, Integer::sum);
     }
 
+    /**
+     * Gets the array of word lengths.
+     *
+     * @param words the words
+     * @return the array of lengths
+     */
     public static final int[] getLengths(final String[] words) {
         return Arrays.stream(words).mapToInt(String::length).toArray();
     }
 
+    /**
+     * Gets the array of length cardinalities.
+     *
+     * The cardinality of a word is its number of distinct characters.
+     *
+     * @param words the words
+     * @return the array of cardinalities
+     */
     public static final int[] getCards(final String[] words) {
         final ToIntFunction<String> distinctCharCount = s -> (int) s.chars().distinct().count();
         return Arrays.stream(words).mapToInt(distinctCharCount).toArray();
diff --git a/src/main/java/cryptator/gen/AbstractCryptaListModel.java b/src/main/java/cryptator/gen/AbstractCryptaListModel.java
index 5a658f7..3f7a5ed 100644
--- a/src/main/java/cryptator/gen/AbstractCryptaListModel.java
+++ b/src/main/java/cryptator/gen/AbstractCryptaListModel.java
@@ -45,10 +45,18 @@ protected AbstractCryptaListModel(final Model model, final String[] words) {
         symbolCount = model.intVar("symbCount", 0, symbolsToVariables.size());
     }
 
+    /**
+     * Gets the symbol count.
+     *
+     * @return the symbol count
+     */
     public final IntVar getSymbolCount() {
         return symbolCount;
     }
 
+    /**
+     * Builds the model.
+     */
     @Override
     public void buildModel() {
         super.buildModel();
@@ -56,13 +64,31 @@ public void buildModel() {
         postChannelingConstraints();
     }
 
+    /**
+     * Post the constraint for the fixed right member.
+     */
     public abstract void postFixedRightMemberConstraints();
 
-    public abstract void postDoublyTrueConstraints(final int lowerBound);
+    /**
+     * Post constraints for doubly true cryptarithms.
+     *
+     * @param lowerBound the lower bound for the sum
+     */
+    public abstract void postDoublyTrueConstraints(int lowerBound);
 
+    /**
+     * Post optional constraints for the numerical precision.
+     *
+     * @param base the arithmetic base
+     */
     public abstract void postPrecisionConstraints(int base);
 
-    public abstract void postHeavyConstraints(final int base);
+    /**
+     * Post heavy constraints for filtering more candidates.
+     *
+     * @param base the arithmetic base
+     */
+    public abstract void postHeavyConstraints(int base);
 
     /**
      * Post a constraint over the maximum number of distinct symbols in the words.
@@ -73,6 +99,9 @@ public void postMaxSymbolCountConstraint(final int max) {
         symbolCount.le(max).post();
     }
 
+    /**
+     * Post symbol count constraint.
+     */
     private void postSymbolCountConstraint() {
         final BoolVar[] symbols = AbstractCryptaListModel.toArray(symbolsToVariables.values());
         model.sum(symbols, "=", symbolCount).post();
@@ -125,6 +154,12 @@ private void postChannelingConstraints() {
         }
     }
 
+    /**
+     * Transform a collection of boolean variables into an array.
+     *
+     * @param vars the boolean variable collection
+     * @return the array
+     */
     private static BoolVar[] toArray(final Collection<BoolVar> vars) {
         return vars.toArray(new BoolVar[vars.size()]);
     }
diff --git a/src/main/java/cryptator/gen/CryptaGenAdd.java b/src/main/java/cryptator/gen/CryptaGenAdd.java
index 70db936..afb73b6 100644
--- a/src/main/java/cryptator/gen/CryptaGenAdd.java
+++ b/src/main/java/cryptator/gen/CryptaGenAdd.java
@@ -68,7 +68,7 @@ public void postDoublyTrueConstraints(final int lb) {
     }
 
     @Override
-    public void postPrecisionConstraints(int base) {
+    public void postPrecisionConstraints(final int base) {
         // Nothing to do.
     }
 
diff --git a/src/main/java/cryptator/gen/CryptaGenCrossword.java b/src/main/java/cryptator/gen/CryptaGenCrossword.java
index 1c3c707..9ca3c7f 100644
--- a/src/main/java/cryptator/gen/CryptaGenCrossword.java
+++ b/src/main/java/cryptator/gen/CryptaGenCrossword.java
@@ -23,7 +23,8 @@ class CryptaCrossPair extends CryptaMemberPair {
 
     private final IntVar[] indices;
 
-    public CryptaCrossPair(final IntVar[] indices, final String[] words, final String prefix, boolean useLenModel) {
+    public CryptaCrossPair(final IntVar[] indices, final String[] words, final String prefix,
+            final boolean useLenModel) {
         super(indices[indices.length - 1], words, prefix, useLenModel);
         this.indices = indices;
     }
@@ -56,7 +57,7 @@ public class CryptaGenCrossword extends AbstractCryptaListModel {
 
     private final CryptaCrossPair[] additions;
 
-    public CryptaGenCrossword(int n, String[] words, boolean useLenModel) {
+    public CryptaGenCrossword(final int n, final String[] words, final boolean useLenModel) {
         super(new Model("Generate-Crossword"), words);
         this.n = n;
         this.grid = new CryptaGridModel(model, n, words.length);
@@ -64,7 +65,7 @@ public CryptaGenCrossword(int n, String[] words, boolean useLenModel) {
         createMembers(useLenModel);
     }
 
-    private void createMembers(boolean useLenModel) {
+    private void createMembers(final boolean useLenModel) {
         for (int i = 0; i < n; i++) {
             final String prefix = "R" + (i + 1) + "_";
             additions[i] = new CryptaCrossPair(grid.getRow(i), words, prefix, useLenModel);
@@ -76,24 +77,12 @@ private void createMembers(boolean useLenModel) {
         }
     }
 
-    private void setSolution() {
-        int[][] solgrid = new int[][] {new int[] {0, 3, 4}, new int[] {1, 5, 7}, new int[] {2, 6, 8}};
-        for (int i = 0; i < solgrid.length; i++) {
-            for (int j = 0; j < solgrid[i].length; j++) {
-                grid.getCell(i, j).eq(solgrid[i][j]).post();
-            }
-        }
-    }
-
     @Override
     public void buildModel() {
         super.buildModel();
         grid.buildModel();
         Stream.of(additions).forEach(CryptaCrossPair::buildModel);
-        // setSolution();
-        // TODO Set search strategy ?
-        // getSolver().setSearch(Search.intVarSearch(ArrayUtils.flatten(grid.getMatrix())));
-
+        // TODO change search strategy ?
     }
 
     @Override
@@ -102,17 +91,17 @@ public void postFixedRightMemberConstraints() {
     }
 
     @Override
-    public void postDoublyTrueConstraints(int lowerBound) {
+    public void postDoublyTrueConstraints(final int lowerBound) {
         throw new UnsupportedOperationException("Not yet implemented");
     }
 
     @Override
-    public void postHeavyConstraints(int base) {
+    public void postHeavyConstraints(final int base) {
         Stream.of(additions).forEach(m -> m.postHeavyConstraints(base));
     }
 
     @Override
-    public void postPrecisionConstraints(int base) {
+    public void postPrecisionConstraints(final int base) {
         // Nothing to do.
     }
 
diff --git a/src/main/java/cryptator/gen/CryptaGenLongMult.java b/src/main/java/cryptator/gen/CryptaGenLongMult.java
index 59ab38c..25f1bdd 100644
--- a/src/main/java/cryptator/gen/CryptaGenLongMult.java
+++ b/src/main/java/cryptator/gen/CryptaGenLongMult.java
@@ -33,7 +33,7 @@ public class CryptaGenLongMult extends AbstractCryptaListModel {
 
     private int arithmeticBase;
 
-    public CryptaGenLongMult(String[] words, int arithmeticBase) {
+    public CryptaGenLongMult(final String[] words, final int arithmeticBase) {
         super(new Model("Generate-Long-Multiplication"), words);
         this.arithmeticBase = arithmeticBase;
         final int[] lengths = getLengths(words);
@@ -45,7 +45,7 @@ public final int getArithmeticBase() {
         return arithmeticBase;
     }
 
-    public final void setArithmeticBase(int arithmeticBase) {
+    public final void setArithmeticBase(final int arithmeticBase) {
         this.arithmeticBase = arithmeticBase;
     }
 
@@ -77,17 +77,17 @@ public void postFixedRightMemberConstraints() {
     }
 
     @Override
-    public void postDoublyTrueConstraints(int lowerBound) {
+    public void postDoublyTrueConstraints(final int lowerBound) {
         throw new UnsupportedOperationException("Doubly true long multiplication is undefined.");
     }
 
     @Override
-    public void postHeavyConstraints(int base) {
+    public void postHeavyConstraints(final int base) {
         // Nothing to do
     }
 
     @Override
-    public void postPrecisionConstraints(int base) {
+    public void postPrecisionConstraints(final int base) {
         final int thresh = AdaptiveSolver.computeThreshold(base);
         longMult.getProductLength().le(thresh).post();
     }
@@ -107,7 +107,7 @@ private String[] getTermWords() {
         return twords;
     }
 
-    private static ICryptaNode recordTermAddition(final String[] terms, String product, int base) {
+    private static ICryptaNode recordTermAddition(final String[] terms, final String product, final int base) {
         ArrayList<ICryptaNode> nodes = new ArrayList<>();
         int exponent = 1;
         for (int i = terms.length - 1; i >= 0; i--) {
@@ -119,7 +119,8 @@ private static ICryptaNode recordTermAddition(final String[] terms, String produ
         return new CryptaNode(CryptaOperator.EQ, addition, new CryptaLeaf(product));
     }
 
-    private static ICryptaNode recordTermMultiplications(String[] terms, String multiplicand, String multiplier) {
+    private static ICryptaNode recordTermMultiplications(final String[] terms, final String multiplicand,
+            final String multiplier) {
         final char[] multipliers = multiplier.toCharArray();
         final ArrayList<ICryptaNode> nodes = new ArrayList<>();
         for (int i = 0; i < terms.length; i++) {
diff --git a/src/main/java/cryptator/gen/CryptaGenMult.java b/src/main/java/cryptator/gen/CryptaGenMult.java
index a608c66..0bfa9b1 100644
--- a/src/main/java/cryptator/gen/CryptaGenMult.java
+++ b/src/main/java/cryptator/gen/CryptaGenMult.java
@@ -23,7 +23,7 @@ class CryptaMemberMult extends CryptaMemberPair {
 
     private final IntVar sumR;
 
-    public CryptaMemberMult(Model model, String[] words, String prefix) {
+    public CryptaMemberMult(final Model model, final String[] words, final String prefix) {
         super(new CryptaMemberLen(model, words, prefix + "L_"), new CryptaMemberLen(model, words, prefix + "R_"));
         final int ub = AbstractCryptaGenModel.getSumLength(words);
         this.sumL = model.intVar("L_sumLength", 0, ub);
@@ -48,7 +48,7 @@ protected void postSymBreakLengthConstraint() {
         getModel().lexLess(left.getWordVars(), right.getWordVars()).post();
     }
 
-    public void postMultPrecisionConstraints(int base) {
+    public void postMultPrecisionConstraints(final int base) {
         getModel().sum(left.lengths, "=", sumL).post();
         getModel().sum(((CryptaMemberLen) right).lengths, "=", sumR).post();
         final int thresh = AdaptiveSolver.computeThreshold(base) + 1;
@@ -56,7 +56,7 @@ public void postMultPrecisionConstraints(int base) {
         sumR.le(thresh).post();
     }
 
-    public void postMultHeavyConstraints(int base) {
+    public void postMultHeavyConstraints(final int base) {
         final ArExpression minL = sumL.sub(left.getWordCount()).add(1);
         final ArExpression minR = sumR.sub(right.getWordCount()).add(1);
         minL.le(sumR).post();
@@ -67,6 +67,8 @@ public void postMultHeavyConstraints(int base) {
 
 public class CryptaGenMult extends AbstractCryptaListModel {
 
+    private final int PRECISION = 1000;
+
     private final CryptaMemberMult multiplication;
 
     public CryptaGenMult(final String[] words) {
@@ -98,9 +100,9 @@ public void postFixedRightMemberConstraints() {
         multiplication.postFixedRightMemberConstraints();
     }
 
-    private int getDoublyCoeff(int i) {
+    private int getDoublyCoeff(final int i) {
         double coeff = Math.log(i) / Math.log((getN() - 1));
-        return (int) Math.round(1000 * coeff);
+        return (int) Math.round(PRECISION * coeff);
 
     }
 
@@ -131,7 +133,7 @@ public void postDoublyTrueConstraints(final int lb) {
     }
 
     @Override
-    public void postPrecisionConstraints(int base) {
+    public void postPrecisionConstraints(final int base) {
         final int thresh = AdaptiveSolver.computeThreshold(base);
         getMaxLength().le(thresh).post();
         multiplication.postMultPrecisionConstraints(base);
diff --git a/src/main/java/cryptator/gen/CryptaListGenerator.java b/src/main/java/cryptator/gen/CryptaListGenerator.java
index 736766c..49188f5 100644
--- a/src/main/java/cryptator/gen/CryptaListGenerator.java
+++ b/src/main/java/cryptator/gen/CryptaListGenerator.java
@@ -37,18 +37,35 @@
 import cryptator.specs.ICryptaSolver;
 import cryptator.tree.TreeUtils;
 
+/**
+ * The Class CryptaListGenerator is the root class for generation.
+ * 
+ * It builds and solves a generation model for cryptarithms.
+ */
 public class CryptaListGenerator implements ICryptaGenerator {
 
+    /** The words. */
     private final WordArray words;
 
+    /** The config. */
     private final CryptagenConfig config;
 
+    /** The logger. */
     private final Logger logger;
 
+    /** The clog. */
     private final ChocoLogger clog;
 
+    /** The error count. */
     private final AtomicInteger errorCount;
 
+    /**
+     * Instantiates a new cryptarithm generator.
+     *
+     * @param words  the word array
+     * @param config the configuration
+     * @param logger the logger
+     */
     public CryptaListGenerator(final WordArray words, final CryptagenConfig config, final Logger logger) {
         super();
         this.words = words;
@@ -58,10 +75,20 @@ public CryptaListGenerator(final WordArray words, final CryptagenConfig config,
         this.errorCount = new AtomicInteger();
     }
 
+    /**
+     * Gets the error count.
+     *
+     * @return the error count
+     */
     public final int getErrorCount() {
         return errorCount.intValue();
     }
 
+    /**
+     * Creates the generation model with respect to the configuration.
+     *
+     * @return the generation model
+     */
     private AbstractCryptaListModel createGenModel() {
         if (config.getGridSize() > 0) {
             return new CryptaGenCrossword(config.getGridSize(), words.getWords(), config.isLightModel());
@@ -74,6 +101,13 @@ private AbstractCryptaListModel createGenModel() {
         }
     }
 
+    /**
+     * Builds the generation solver.
+     * 
+     * It creates, builds and configures the generation model.
+     *
+     * @return the generation solver
+     */
     private ICryptaGenSolver buildGenSolver() {
         final AbstractCryptaListModel gen = createGenModel();
         gen.buildModel();
@@ -93,6 +127,13 @@ private ICryptaGenSolver buildGenSolver() {
         return gen;
     }
 
+    /**
+     * Builds the consumer for candidate cryptarithms .
+     *
+     * @param gen      the generation model
+     * @param consumer the consumer for valid cryptarithms
+     * @return the candidate consumer
+     */
     private Consumer<ICryptaNode> buildConsumer(final IChocoModel gen,
             final BiConsumer<ICryptaNode, ICryptaSolution> consumer) {
         final Consumer<ICryptaNode> cons = new LogConsumer(gen);
@@ -100,6 +141,12 @@ private Consumer<ICryptaNode> buildConsumer(final IChocoModel gen,
         return config.isDryRun() ? cons : cons.andThen(new GenerateConsumer(solver, consumer));
     }
 
+    /**
+     * Solve the candidates in sequential.
+     *
+     * @param gen  the generation solver
+     * @param cons the candidate consumer
+     */
     private void sequentialSolve(final ICryptaGenSolver gen, final Consumer<ICryptaNode> cons) {
         final Solver s = gen.getSolver();
         while (s.solve()) {
@@ -107,6 +154,13 @@ private void sequentialSolve(final ICryptaGenSolver gen, final Consumer<ICryptaN
         }
     }
 
+    /**
+     * Solve the candidates in parallel (experimental).
+     *
+     * @param gen      the generation solver
+     * @param cons     the candidate consumer
+     * @param nthreads the number of threads
+     */
     private static void parallelSolve(final ICryptaGenSolver gen, final Consumer<ICryptaNode> cons,
             final int nthreads) {
         final ExecutorService executor = Executors.newFixedThreadPool(nthreads);
@@ -142,16 +196,30 @@ public long generate(final BiConsumer<ICryptaNode, ICryptaSolution> consumer) th
         return gen.getSolver().getSolutionCount();
     }
 
+    /**
+     * The LogConsumer logs the candidate cryptarithm.
+     */
     // FIXME are consumers thread-safe ? they are used in parallel !
     private class LogConsumer implements Consumer<ICryptaNode> {
 
+        /** The solution. */
         private final Solution solution;
 
+        /**
+         * Instantiates a new log consumer.
+         *
+         * @param gen the generation model
+         */
         LogConsumer(final IChocoModel gen) {
             super();
             solution = new Solution(gen.getModel());
         }
 
+        /**
+         * Accept the candidate cryptarithm.
+         *
+         * @param t the candidate cryptarithm
+         */
         @Override
         public void accept(final ICryptaNode t) {
             clog.logOnSolution(solution);
@@ -161,12 +229,23 @@ public void accept(final ICryptaNode t) {
         }
     }
 
+    /**
+     * The Class GenerateConsumer solves the candidate cryptarithm.
+     */
     private class GenerateConsumer implements Consumer<ICryptaNode> {
 
+        /** The solver. */
         private final ICryptaSolver solver;
 
+        /** The internal consumer for valid cryptarithm. */
         private final BiConsumer<ICryptaNode, ICryptaSolution> internal;
 
+        /**
+         * Instantiates a new generate consumer.
+         *
+         * @param solver   the cryptarithm solver
+         * @param internal the internal consumer for valid cryptarithm
+         */
         GenerateConsumer(final ICryptaSolver solver, final BiConsumer<ICryptaNode, ICryptaSolution> internal) {
             super();
             this.solver = solver;
@@ -174,6 +253,11 @@ private class GenerateConsumer implements Consumer<ICryptaNode> {
             this.solver.limitSolution(2);
         }
 
+        /**
+         * Builds the consumer of valid cryptarithms.
+         *
+         * @return the cryptarithm consumer
+         */
         private CryptaBiConsumer buildBiConsumer() {
             CryptaBiConsumer consumer = new CryptaBiConsumer(logger);
             if (config.isCheckSolution()) {
@@ -182,6 +266,11 @@ private CryptaBiConsumer buildBiConsumer() {
             return consumer;
         }
 
+        /**
+         * Accept the candidate cryptarithm.
+         *
+         * @param t the candidate
+         */
         @Override
         public void accept(final ICryptaNode t) {
             try {
diff --git a/src/main/java/cryptator/gen/GenerateUtil.java b/src/main/java/cryptator/gen/GenerateUtil.java
index 91f7bc2..55e5117 100644
--- a/src/main/java/cryptator/gen/GenerateUtil.java
+++ b/src/main/java/cryptator/gen/GenerateUtil.java
@@ -21,30 +21,73 @@
 import cryptator.tree.CryptaLeaf;
 import cryptator.tree.CryptaNode;
 
-public class GenerateUtil {
+/**
+ * The Class GenerateUtil provides utilities for building cryptarithm tree.
+ * 
+ * It is used by generation models for recording their solutions.
+ */
+public final class GenerateUtil {
 
+    /**
+     * Unusable private constructor.
+     */
     private GenerateUtil() {
         super();
     }
 
+    /**
+     * The stream of present words of the model.
+     *
+     * @param model the generation model
+     * @return the stream of present words
+     */
     public static Stream<String> wordStream(final ICryptaGenModel model) {
         final BoolVar[] v = model.getWordVars();
         final String[] w = model.getWords();
         return IntStream.range(0, model.getN()).filter(i -> v[i].isInstantiatedTo(1)).mapToObj(i -> w[i]);
     }
 
+    /**
+     * The stream of present word leaves.
+     * 
+     * A leaf is created for each present word of the model.
+     * 
+     * @param model the generation model
+     * @return the stream of present leaves
+     */
     public static Stream<ICryptaNode> leafStream(final ICryptaGenModel model) {
         return wordStream(model).map(CryptaLeaf::new).map(ICryptaNode.class::cast);
     }
 
+    /**
+     * Record a string with the present words.
+     *
+     * @param model     the generation model
+     * @param separator the word separator
+     * @return the string of present words
+     */
     public static String recordString(final ICryptaGenModel model, final String separator) {
         return wordStream(model).collect(Collectors.joining(separator));
     }
 
+    /**
+     * Reduce the nodes by an operation.
+     *
+     * @param operator the operator
+     * @param nodes    the nodes to reduce
+     * @return the reduced node
+     */
     public static ICryptaNode reduceOperation(final CryptaOperator operator, final ICryptaNode... nodes) {
         return reduceOperation(operator, Stream.of(nodes));
     }
 
+    /**
+     * Reduce the nodes by an operation.
+     *
+     * @param operator   the operator
+     * @param nodeStream the stream of nodes to reduce
+     * @return the reduced node
+     */
     public static ICryptaNode reduceOperation(final CryptaOperator operator, final Stream<ICryptaNode> nodeStream) {
         BinaryOperator<ICryptaNode> binop = (a, b) -> {
             if (a == null) {
@@ -55,23 +98,58 @@ public static ICryptaNode reduceOperation(final CryptaOperator operator, final S
         return nodeStream.reduce(null, binop);
     }
 
+    /**
+     * Record the addition of present words.
+     *
+     * @param model the generation model
+     * @return the sum node
+     */
     public static ICryptaNode recordAddition(final ICryptaGenModel model) {
         return reduceOperation(CryptaOperator.ADD, leafStream(model));
     }
 
+    /**
+     * Record the addition of two nodes.
+     *
+     * @param left  the left node
+     * @param right the right node
+     * @return the sum node
+     */
     public static ICryptaNode recordAddition(final ICryptaGenModel left, final ICryptaGenModel right) {
         return reduceOperation(CryptaOperator.EQ, recordAddition(left), recordAddition(right));
     }
 
+    /**
+     * Record the multiplication of present words.
+     *
+     * @param model the generation model
+     * @return the product node
+     */
     public static ICryptaNode recordMultiplication(final ICryptaGenModel model) {
         return reduceOperation(CryptaOperator.MUL, leafStream(model));
     }
 
+    /**
+     * Record the multiplication of two nodes.
+     *
+     * @param left  the left node
+     * @param right the right node
+     * @return the product node
+     */
     public static ICryptaNode recordMultiplication(final ICryptaGenModel left, final ICryptaGenModel right) {
         return reduceOperation(CryptaOperator.EQ, recordMultiplication(left), recordMultiplication(right));
     }
 
-    public static ICryptaNode recordMultiplication(String multiplicand, String multiplier, String product) {
+    /**
+     * Record a short multiplication.
+     *
+     * @param multiplicand the multiplicand word
+     * @param multiplier   the multiplier word
+     * @param product      the product word
+     * @return the short multiplication node
+     */
+    public static ICryptaNode recordMultiplication(final String multiplicand, final String multiplier,
+            final String product) {
         return new CryptaNode(CryptaOperator.EQ,
                 new CryptaNode(CryptaOperator.MUL, new CryptaLeaf(multiplicand), new CryptaLeaf(multiplier)),
                 new CryptaLeaf(product));
diff --git a/src/main/java/cryptator/gen/member/CryptaMemberPair.java b/src/main/java/cryptator/gen/member/CryptaMemberPair.java
index 5a33368..f520411 100644
--- a/src/main/java/cryptator/gen/member/CryptaMemberPair.java
+++ b/src/main/java/cryptator/gen/member/CryptaMemberPair.java
@@ -23,26 +23,26 @@ public class CryptaMemberPair implements ICryptaGenSolver {
 
     protected final AbstractCryptaGenModel right;
 
-    protected CryptaMemberPair(CryptaMemberLen left, CryptaMemberLen right) {
+    protected CryptaMemberPair(final CryptaMemberLen left, final CryptaMemberLen right) {
         super();
         this.left = left;
         this.right = right;
     }
 
-    public CryptaMemberPair(final Model model, final String[] words, final String prefix, boolean useMemberLen) {
+    public CryptaMemberPair(final Model model, final String[] words, final String prefix, final boolean useMemberLen) {
         super();
         left = buildLeftMember(model, words, prefix, useMemberLen);
         right = new CryptaMemberElt(model, words, prefix + "R_");
     }
 
-    public CryptaMemberPair(final IntVar index, final String[] words, final String prefix, boolean useMemberLen) {
+    public CryptaMemberPair(final IntVar index, final String[] words, final String prefix, final boolean useMemberLen) {
         super();
         left = buildLeftMember(index.getModel(), words, prefix, useMemberLen);
         right = new CryptaMemberElt(index, words, prefix + "R_");
     }
 
     private static final CryptaMemberLen buildLeftMember(final Model model, final String[] words, final String prefix,
-            boolean useMemberLen) {
+            final boolean useMemberLen) {
         return useMemberLen ? new CryptaMemberLen(model, words, prefix + "L_")
                 : new CryptaMemberCard(model, words, prefix + "L_");
     }
diff --git a/src/main/java/cryptator/gen/pattern/CryptaGridModel.java b/src/main/java/cryptator/gen/pattern/CryptaGridModel.java
index f3511f3..132ea56 100644
--- a/src/main/java/cryptator/gen/pattern/CryptaGridModel.java
+++ b/src/main/java/cryptator/gen/pattern/CryptaGridModel.java
@@ -15,16 +15,30 @@
 import cryptator.gen.AbstractCryptaGenModel;
 import cryptator.specs.IChocoModel;
 
+/**
+ * The Class CryptaGridModel assigns distinct words to a square grid.
+ */
 public final class CryptaGridModel implements IChocoModel {
 
+    /** The model. */
     private final Model model;
 
+    /** The grid of word indices. */
     private final IntVar[][] grid;
 
+    /** The transposed grid of word indices. */
     private final IntVar[][] tgrid;
 
+    /** The format for printing the grid. */
     private final String format;
 
+    /**
+     * Instantiates a new grid model.
+     *
+     * @param model the model
+     * @param n     the grid dimension is 'n x n'
+     * @param m     the number of words
+     */
     public CryptaGridModel(final Model model, final int n, final int m) {
         super();
         this.model = model;
@@ -34,10 +48,16 @@ public CryptaGridModel(final Model model, final int n, final int m) {
         this.format = " %" + precision + "d";
     }
 
+    /**
+     * Post all different constraint for the word indices.
+     */
     private void postAllDifferentConstraint() {
         model.allDifferent(ArrayUtils.flatten(grid)).post();
     }
 
+    /**
+     * Post symmetry breaking constraints over the word indices.
+     */
     private void postSymmetryBreakingConstraints() {
         final int n = size();
         if (n > 1) {
@@ -51,6 +71,9 @@ private void postSymmetryBreakingConstraints() {
         }
     }
 
+    /**
+     * Builds the grid model.
+     */
     public void buildModel() {
         postAllDifferentConstraint();
         postSymmetryBreakingConstraints();
@@ -61,31 +84,71 @@ public Model getModel() {
         return model;
     }
 
+    /**
+     * Gets the grid size
+     * 
+     * @return the grid size
+     */
     public int size() {
         return grid.length;
     }
 
-    public IntVar getCell(int i, int j) {
+    /**
+     * Gets the variable of the grid.
+     *
+     * @param i the row
+     * @param j the column
+     * @return the grid variable
+     */
+    public IntVar getCell(final int i, final int j) {
         return grid[i][j];
     }
 
-    public IntVar[] getRow(int i) {
+    /**
+     * Gets the i-th row of the grid.
+     *
+     * @param i the row index
+     * @return the row array of variables
+     */
+    public IntVar[] getRow(final int i) {
         return grid[i];
     }
 
-    public IntVar[] getCol(int i) {
+    /**
+     * Gets the i-th column of the grid.
+     *
+     * @param i the column index
+     * @return the row array of variables
+     */
+    public IntVar[] getCol(final int i) {
         return tgrid[i];
     }
 
+    /**
+     * Gets the matrix of grid variables.
+     *
+     * @return the matrix of word indices
+     */
     public IntVar[][] getMatrix() {
         return grid;
     }
 
+    /**
+     * Gets the transposed matrix.
+     *
+     * @return the transpose
+     */
     public IntVar[][] getTranspose() {
         return tgrid;
     }
 
-    public String toString(String[] words) {
+    /**
+     * To string with word mapping.
+     *
+     * @param words the words mapped to the indices
+     * @return the grid of words
+     */
+    public String toString(final String[] words) {
         final int n = size();
         final StringBuilder b = new StringBuilder();
         final int maxlen = AbstractCryptaGenModel.getMaxLength(words);
@@ -99,6 +162,11 @@ public String toString(String[] words) {
         return b.toString();
     }
 
+    /**
+     * To string with indices.
+     *
+     * @return the grid of indices
+     */
     @Override
     public String toString() {
         final StringBuilder b = new StringBuilder();
diff --git a/src/main/java/cryptator/gen/pattern/CryptaLongMultModel.java b/src/main/java/cryptator/gen/pattern/CryptaLongMultModel.java
index dae858b..9633488 100644
--- a/src/main/java/cryptator/gen/pattern/CryptaLongMultModel.java
+++ b/src/main/java/cryptator/gen/pattern/CryptaLongMultModel.java
@@ -20,37 +20,65 @@
 
 import cryptator.specs.IChocoModel;
 
+/**
+ * The Class builds a generation model for long multiplication.
+ * 
+ * It does not inherit nor use members because of the strength of the
+ * constraints over the operands.
+ */
 public class CryptaLongMultModel implements IChocoModel {
 
+    /** The word cardinalities, i.e. the number of distinct characters. */
     private final int[] cards;
 
+    /** The word lengths, i.e. the number of characters. */
     private final int[] lengths;
 
+    /** The model. */
     private final Model model;
 
+    /** The multiplicand index. */
     private final IntVar multiplicand;
 
+    /** The multiplier index. */
     private final IntVar multiplier;
 
+    /** The product index. */
     private final IntVar product;
 
+    /** The term indices. */
     private final IntVar[] terms;
 
+    /** The term presences. */
     private final BoolVar[] presences;
 
+    /** The multiplicand length. */
     private final IntVar mdLength;
 
+    /** The multiplier length. */
     private final IntVar mrLength;
 
+    /** The product length. */
     private final IntVar prLength;
 
+    /** The term lengths. */
     private final IntVar[] termLengths;
 
+    /** The multiplier cardinality, its number of distinct characters. */
     private final IntVar mrCard;
 
-    private int maxProductLength = 5;
-
-    public CryptaLongMultModel(Model model, final int[] lengths, final int[] cards) {
+    /** The Constant maxProductLength. */
+    // TODO Define properly
+    private static final int maxProductLength = 5;
+
+    /**
+     * Instantiates a new model for the long multiplication.
+     *
+     * @param model   the model
+     * @param lengths the word lengths
+     * @param cards   the word cardinalities
+     */
+    public CryptaLongMultModel(final Model model, final int[] lengths, final int[] cards) {
         this.model = model;
         this.lengths = lengths;
         this.cards = cards;
@@ -74,30 +102,65 @@ public Model getModel() {
         return model;
     }
 
+    /**
+     * Gets the multiplicand index.
+     *
+     * @return the multiplicand index
+     */
     public int getMultiplicandIndex() {
         return multiplicand.getValue();
     }
 
+    /**
+     * Gets the multiplier index.
+     *
+     * @return the multiplier index
+     */
     public int getMultiplierIndex() {
         return multiplier.getValue();
     }
 
+    /**
+     * Gets the product index.
+     *
+     * @return the product index
+     */
     public int getProductIndex() {
         return product.getValue();
     }
 
+    /**
+     * Gets the product length.
+     *
+     * @return the product length
+     */
     public IntVar getProductLength() {
         return prLength;
     }
 
+    /**
+     * Gets the product.
+     *
+     * @return the product
+     */
     public IntVar getProduct() {
         return product;
     }
 
+    /**
+     * Gets the word indices.
+     * 
+     * @return the word indices
+     */
     public IntVar[] getWordIndices() {
         return ArrayUtils.append(ArrayUtils.toArray(multiplicand, multiplier, product), terms);
     }
 
+    /**
+     * Gets the term indices.
+     *
+     * @return the term indices
+     */
     public int[] getTermIndices() {
         int n = mrCard.getValue();
         int[] indices = new int[n];
@@ -107,16 +170,22 @@ public int[] getTermIndices() {
         return indices;
     }
 
-    private static void ge1(ArExpression e1, ArExpression e2) {
+    private static void ge1(final ArExpression e1, final ArExpression e2) {
         e1.ge(e2).post();
         e1.le(e2.add(1)).post();
     }
 
+    /**
+     * Post the product length constraints.
+     */
     private void postPRLenConstraints() {
         ge1(prLength, mdLength.add(mrLength).sub(1));
         prLength.ge(termLengths[0].add(mrLength).sub(1)).post();
     }
 
+    /**
+     * Post the all different constraint on the word indices.
+     */
     private void postAllDifferent() {
         final int n = lengths.length;
         model.allDifferentUnderCondition(ArrayUtils.concat(terms, product), new ExceptN(n), true).post();
@@ -124,6 +193,9 @@ private void postAllDifferent() {
         terms[maxProductLength].eq(n).post();
     }
 
+    /**
+     * Post the channeling between the term indices and lengths.
+     */
     private void postTermLenChanneling() {
         final int n = lengths.length;
         final IntVar[] vars = new IntVar[n + 1];
@@ -137,18 +209,28 @@ private void postTermLenChanneling() {
         }
     }
 
+    /**
+     * Post the channeling constraint between the indices and lengths of the
+     * operands of the short multiplication.
+     */
     private void postMultLenChanneling() {
         model.element(mdLength, lengths, multiplicand).post();
         model.element(mrLength, lengths, multiplier).post();
         model.element(prLength, lengths, product).post();
     }
 
+    /**
+     * Post the constraint on the term lengths.
+     */
     private void postTermLenConstraints() {
         for (int i = 0; i < termLengths.length; i++) {
             ge1(termLengths[i], mdLength);
         }
     }
 
+    /**
+     * Post symmetry breaking constraint by ordering terms.
+     */
     private void postTermOrderingConstraints() {
         for (int i = 0; i < terms.length; i++) {
             model.reifyXneC(terms[i], lengths.length, presences[i]);
@@ -156,11 +238,17 @@ private void postTermOrderingConstraints() {
         model.decreasing(presences, 0).post();
     }
 
+    /**
+     * Post the constraint for counting the terms.
+     */
     private void postTermCountConstraints() {
         model.element(mrCard, cards, multiplier).post();
         model.sum("presences", presences).eq(mrCard).post();
     }
 
+    /**
+     * Builds the model.
+     */
     public void buildModel() {
         postAllDifferent();
 
@@ -174,17 +262,23 @@ public void buildModel() {
         postTermOrderingConstraints();
     }
 
-    private void toString(StringBuilder b, IntVar idx, IntVar len) {
+    private void toString(final StringBuilder b, final IntVar idx, final IntVar len) {
         toString(b, idx, len, Optional.empty());
     }
 
-    private void toString(StringBuilder b, IntVar idx, IntVar len, Optional<IntVar> card) {
+    private void toString(final StringBuilder b, final IntVar idx, final IntVar len, final Optional<IntVar> card) {
         b.append(idx.getValue()).append("(").append(len.getValue());
-        if (card.isPresent())
+        if (card.isPresent()) {
             b.append("-").append(card.get().getValue());
+        }
         b.append(") ");
     }
 
+    /**
+     * To string.
+     *
+     * @return the string
+     */
     @Override
     public String toString() {
         StringBuilder b = new StringBuilder();
@@ -202,17 +296,26 @@ public String toString() {
         return b.toString();
     }
 
+    /**
+     * The Class ExceptN for the all different constraint
+     */
     private static class ExceptN implements Condition {
 
+        /** The dummy index. */
         private final int n;
 
-        protected ExceptN(int n) {
+        /**
+         * Instantiates a new condition.
+         *
+         * @param n the dummy index
+         */
+        protected ExceptN(final int n) {
             super();
             this.n = n;
         }
 
         @Override
-        public boolean holdOnVar(IntVar x) {
+        public boolean holdOnVar(final IntVar x) {
             return !x.contains(n);
         }
 
diff --git a/src/main/java/cryptator/solver/AbstractCryptaSolution.java b/src/main/java/cryptator/solver/AbstractCryptaSolution.java
index 4820023..3bea9bd 100644
--- a/src/main/java/cryptator/solver/AbstractCryptaSolution.java
+++ b/src/main/java/cryptator/solver/AbstractCryptaSolution.java
@@ -9,6 +9,7 @@
 package cryptator.solver;
 
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.TreeMap;
 import java.util.function.BiConsumer;
 
@@ -53,11 +54,11 @@ public void forEach(final BiConsumer<? super Character, ? super E> action) {
     public String toString() {
         final StringBuilder b1 = new StringBuilder();
         final StringBuilder b2 = new StringBuilder();
-        for (Character symbol : symbolsToDigits.keySet()) {
-            final String domain = getDomain(symbolsToDigits.get(symbol));
+        for (Entry<Character, E> e : symbolsToDigits.entrySet()) {
+            final String domain = getDomain(e.getValue());
             final int length = Math.max(1, domain.length());
             final String format = " %" + length + "s|";
-            b1.append(String.format(format, symbol));
+            b1.append(String.format(format, e.getKey()));
             b2.append(String.format(format, domain));
         }
         return b1.toString() + "\n" + b2.toString();
diff --git a/src/main/java/cryptator/solver/AbstractModelerNodeConsumer.java b/src/main/java/cryptator/solver/AbstractModelerNodeConsumer.java
index 34f43ce..28cc073 100644
--- a/src/main/java/cryptator/solver/AbstractModelerNodeConsumer.java
+++ b/src/main/java/cryptator/solver/AbstractModelerNodeConsumer.java
@@ -101,7 +101,6 @@ public void postConstraints() throws CryptaModelException {
     }
 
     public void configureSearch() {
-        // model.getSolver().showDecisions();
         final int searchType = config.getSearchStrategy();
         if (searchType == 1) {
             IntVar[] vars = symbolsToVariables.values().toArray(new IntVar[symbolsToVariables.size()]);
diff --git a/src/main/java/cryptator/solver/CryptaBignumModeler.java b/src/main/java/cryptator/solver/CryptaBignumModeler.java
index 6ae5374..99b0db0 100644
--- a/src/main/java/cryptator/solver/CryptaBignumModeler.java
+++ b/src/main/java/cryptator/solver/CryptaBignumModeler.java
@@ -90,12 +90,10 @@ private ArExpression[] applyADD(final ArExpression[] a, final ArExpression[] b)
         for (int i = 0; i < m; i++) {
             c[i] = CryptaOperator.ADD.getExpression().apply(a[i], b[i]);
         }
-        // Can only enter in one loop
-        for (int i = m; i < a.length; i++) {
-            c[i] = a[i];
-        }
-        for (int i = m; i < b.length; i++) {
-            c[i] = b[i];
+        if (a.length > m) {
+            System.arraycopy(a, m, c, m, a.length - m);
+        } else {
+            System.arraycopy(b, m, c, m, b.length - m);
         }
         return c;
     }
diff --git a/src/test/java/cryptator/BignumTest.java b/src/test/java/cryptator/BignumTest.java
index b1bb888..730172a 100644
--- a/src/test/java/cryptator/BignumTest.java
+++ b/src/test/java/cryptator/BignumTest.java
@@ -199,31 +199,16 @@ public void testSetBase2() throws CryptaParserException, CryptaModelException, C
     // Tests from SolverTest class
     @Test
     public void testSendMoreMoneyList2() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
         t.testNotUNIQUE("send+more=money; a+b=c");
     }
 
     @Test
     public void testSendMoreMoneyList3() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
         t.testSAT("send+more=money; a+b=c");
     }
 
     @Test
-    public void testSendMoreMoneyList4() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money; s+e=n");
-    }
-
-    @Test
-    public void testSendMoreMoneyList5() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money;;; s+e=n");
-    }
-
-    @Test
-    public void testSendMoreMoneyList6() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money; s+e=n;");
+    public void testUnsatSendMoreMoneyList() throws CryptaParserException, CryptaModelException, CryptaSolverException {
+        t.testUNSAT("send+more=money; s+e=n", "send+more=money;;; s+e=n", "send+more=money; s+e=n;");
     }
 }
diff --git a/src/test/java/cryptator/CrossModelTest.java b/src/test/java/cryptator/CrossModelTest.java
index 09c6958..e820e56 100644
--- a/src/test/java/cryptator/CrossModelTest.java
+++ b/src/test/java/cryptator/CrossModelTest.java
@@ -17,25 +17,27 @@
 
 public class CrossModelTest {
 
-    private void testCrosswordModel(int size, String[] words, int expectedSolutionCount) {
+    private void testCrosswordModel(final int size, final String[] words, final int expectedSolutionCount) {
         testCrosswordModel(size, words, true, expectedSolutionCount);
         testCrosswordModel(size, words, false, expectedSolutionCount);
     }
 
-    private void testCrosswordModel(int size, String[] words, boolean useLenModel, int expectedSolutionCount) {
+    private void testCrosswordModel(final int size, final String[] words, final boolean useLenModel,
+            final int expectedSolutionCount) {
         final CryptaGenCrossword m = new CryptaGenCrossword(size, words, useLenModel);
         m.buildModel();
         // System.out.println(m.getModel());
         assertEquals(expectedSolutionCount, m.getModel().getSolver().streamSolutions().count());
     }
 
-    private void testHeavyCrosswordModel(int size, String[] words, int expectedSolutionCount) {
+    private void testHeavyCrosswordModel(final int size, final String[] words, final int expectedSolutionCount) {
         testHeavyCrosswordModel(size, words, true, expectedSolutionCount);
         testHeavyCrosswordModel(size, words, false, expectedSolutionCount);
 
     }
 
-    private void testHeavyCrosswordModel(int size, String[] words, boolean useLenModel, int expectedSolutionCount) {
+    private void testHeavyCrosswordModel(final int size, final String[] words, final boolean useLenModel,
+            final int expectedSolutionCount) {
         final CryptaGenCrossword m = new CryptaGenCrossword(size, words, useLenModel);
         m.buildModel();
         m.postHeavyConstraints(10);
diff --git a/src/test/java/cryptator/GenModelTest.java b/src/test/java/cryptator/GenModelTest.java
index 7af49b0..739a6c0 100644
--- a/src/test/java/cryptator/GenModelTest.java
+++ b/src/test/java/cryptator/GenModelTest.java
@@ -43,17 +43,17 @@ public void postFixedRightMemberConstraints() {
     }
 
     @Override
-    public void postDoublyTrueConstraints(int lowerBound) {
+    public void postDoublyTrueConstraints(final int lowerBound) {
         // Nothing to do.
     }
 
     @Override
-    public void postPrecisionConstraints(int base) {
+    public void postPrecisionConstraints(final int base) {
         // Nothing to do.
     }
 
     @Override
-    public void postHeavyConstraints(int base) {
+    public void postHeavyConstraints(final int base) {
         // Nothing to do.
     }
 
diff --git a/src/test/java/cryptator/GenerateTest.java b/src/test/java/cryptator/GenerateTest.java
index 1262ead..d47d311 100644
--- a/src/test/java/cryptator/GenerateTest.java
+++ b/src/test/java/cryptator/GenerateTest.java
@@ -52,13 +52,13 @@ private void testGenerate(final int expectedSolCount, final OptionalInt expected
         assertEquals(expectedSolCount, cons.getSolutionCount());
     }
 
-    private void testGenerate(final int expectedSolCount, final WordArray wordArray, int gridSize)
+    private void testGenerate(final int expectedSolCount, final WordArray wordArray, final int gridSize)
             throws CryptaModelException {
         testGenerate(expectedSolCount, OptionalInt.empty(), wordArray, 0);
     }
 
     private void testGenerate(final int expectedSolCount, final OptionalInt expectedCandCount,
-            final WordArray wordArray, int gridSize) throws CryptaModelException {
+            final WordArray wordArray, final int gridSize) throws CryptaModelException {
         configure(gridSize, false, false);
         testGenerate(expectedSolCount, expectedCandCount, wordArray);
         configure(gridSize, false, true);
@@ -70,7 +70,7 @@ private void testGenerate(final int expectedSolCount, final OptionalInt expected
     }
 
     private void testHeavyGenerate(final int expectedSolCount, final OptionalInt expectedCandCount,
-            final WordArray wordArray, int gridSize) throws CryptaModelException {
+            final WordArray wordArray, final int gridSize) throws CryptaModelException {
         configure(gridSize, false, false);
         testGenerate(expectedSolCount, expectedCandCount, wordArray);
         configure(gridSize, true, false);
@@ -87,6 +87,17 @@ private void testMultGenerate(final int expectedSolCount, final WordArray wordAr
         config.setMultModel(false);
     }
 
+    private void testLongMultGenerate(final int expectedSolCount, final WordArray wordArray)
+            throws CryptaModelException {
+        JULogUtil.configureSilentLoggers();
+        config.setLongMultModel(true);
+        configure(0, false, false);
+        testGenerate(expectedSolCount, OptionalInt.empty(), wordArray);
+        configure(0, false, true);
+        testGenerate(expectedSolCount, OptionalInt.empty(), wordArray);
+        config.setLongMultModel(false);
+    }
+
     @Test
     public void testSendMoreMoney() throws CryptaModelException {
         final WordArray words = new WordArray(Arrays.asList("send", "more", "money"), null);
@@ -191,4 +202,16 @@ public void testMult5() throws CryptaModelException {
         testMultGenerate(2, words);
     }
 
+    @Test
+    public void testLongMult1() throws CryptaModelException {
+        WordArray words = new WordArray(Arrays.asList("who", "is", "hobs", "hawi", "mosis"), null);
+        testLongMultGenerate(1, words);
+    }
+
+    @Test
+    public void testLongMult3() throws CryptaModelException {
+        WordArray words = new WordArray(Arrays.asList("get", "by", "babe", "beare"), null);
+        testLongMultGenerate(1, words);
+    }
+
 }
diff --git a/src/test/java/cryptator/GridModelTest.java b/src/test/java/cryptator/GridModelTest.java
index f441bec..62bb0f4 100644
--- a/src/test/java/cryptator/GridModelTest.java
+++ b/src/test/java/cryptator/GridModelTest.java
@@ -17,7 +17,7 @@
 
 public class GridModelTest {
 
-    private void testGridModel(int size, int words, int expectedSolutionCount) {
+    private void testGridModel(final int size, final int words, final int expectedSolutionCount) {
         CryptaGridModel m = new CryptaGridModel(new Model(), size, words);
         m.buildModel();
         assertEquals(expectedSolutionCount, m.getModel().getSolver().streamSolutions().count());
diff --git a/src/test/java/cryptator/LongMultModelTest.java b/src/test/java/cryptator/LongMultModelTest.java
index f357595..fe55caf 100644
--- a/src/test/java/cryptator/LongMultModelTest.java
+++ b/src/test/java/cryptator/LongMultModelTest.java
@@ -16,11 +16,11 @@
 
 public class LongMultModelTest {
 
-    public void testLongMultModel(int expectedSolutionCount, int[] lengths) {
+    public void testLongMultModel(final int expectedSolutionCount, final int[] lengths) {
         testLongMultModel(expectedSolutionCount, lengths, lengths);
     }
 
-    public void testLongMultModel(int expectedSolutionCount, int[] lengths, int[] cards) {
+    public void testLongMultModel(final int expectedSolutionCount, final int[] lengths, final int[] cards) {
         CryptaLongMultModel m = new CryptaLongMultModel(new Model(), lengths, cards);
         m.buildModel();
         Assert.assertEquals(expectedSolutionCount, m.getSolver().streamSolutions().count());
diff --git a/src/test/java/cryptator/MultTest.java b/src/test/java/cryptator/MultTest.java
index 75c3b87..fd42fb8 100644
--- a/src/test/java/cryptator/MultTest.java
+++ b/src/test/java/cryptator/MultTest.java
@@ -17,11 +17,11 @@
 
 public class MultTest {
 
-    private void testMultModel(int expectedSolutionCount, String[] words) {
+    private void testMultModel(final int expectedSolutionCount, final String[] words) {
         testMultModel(expectedSolutionCount, words, false);
     }
 
-    private void testMultModel(int expectedSolutionCount, String[] words, boolean isDoublyTrue) {
+    private void testMultModel(final int expectedSolutionCount, final String[] words, final boolean isDoublyTrue) {
         final CryptaGenMult m = new CryptaGenMult(words);
         m.buildModel();
         m.postPrecisionConstraints(10);
@@ -41,10 +41,11 @@ private void testMultModel(int expectedSolutionCount, String[] words, boolean is
 
     }
 
-    private void testGenLongMultModel(int expectedSolutionCount, String[] words) {
+    private void testGenLongMultModel(final int expectedSolutionCount, final String[] words) {
         final CryptaGenLongMult m = new CryptaGenLongMult(words, 10);
         m.buildModel();
-
+        m.postPrecisionConstraints(10);
+        m.postHeavyConstraints(10);
 //        System.out.println(m.getModel());
 //        Solution sol = new Solution(m.getModel());
 //        m.getSolver().streamSolutions().forEach(s -> {
@@ -94,7 +95,7 @@ public void testLongMult1() {
         testGenLongMultModel(22, words);
     }
 
-    @Test // (expected = InvalidSolutionException.class)
+    @Test
     public void testLongMult2() {
         final String[] words = new String[] {"who", "is", "hobs", "hawi", "mosis"};
         testGenLongMultModel(18, words);
diff --git a/src/test/java/cryptator/ProductTest.java b/src/test/java/cryptator/ProductTest.java
index ae5da23..c4a6ba1 100644
--- a/src/test/java/cryptator/ProductTest.java
+++ b/src/test/java/cryptator/ProductTest.java
@@ -19,11 +19,14 @@
 public class ProductTest {
 
     private Model model;
-    private IntVar copper, neon, iron, silver, result;
+    private IntVar copper;
+    private IntVar neon;
+    private IntVar iron;
+    private IntVar silver;
+    private IntVar result;
 
     /***
-     * Tests if choco can solve "copper*neon=iron*silver" via various way of writing
-     * constraints
+     * Tests "copper*neon=iron*silver" with different models.
      */
     @Before
     public void setup() {
@@ -89,7 +92,7 @@ public void model2() {
     }
 
     /***
-     * Creating a model using the operators function given by IntVar
+     * Create a model using the operators function given by IntVar.
      */
     @Test
     @Ignore("It is a choco issue")
@@ -101,8 +104,9 @@ public void model3() {
     }
 
     /***
-     * Creating a model using the operators function given by IntVar without using
-     * result as an intermediary
+     * Create a model using the operators function given by the IntVar.
+     * 
+     * It does not use result as an intermediary
      */
     @Test
     @Ignore("It is a choco issue")
diff --git a/src/test/java/cryptator/SolverTest.java b/src/test/java/cryptator/SolverTest.java
index 02a3d8b..d6027f4 100644
--- a/src/test/java/cryptator/SolverTest.java
+++ b/src/test/java/cryptator/SolverTest.java
@@ -82,19 +82,25 @@ public void testSAT(final String cryptarithm, final int solutionCount)
         assertEquals("solution count " + cryptarithm, solutionCount, testSolve(cryptarithm, true));
     }
 
-    public void testUNSAT(final String cryptarithm) throws CryptaModelException, CryptaSolverException {
-        assertEquals("solution count " + cryptarithm, 0, testSolve(cryptarithm, false));
+    public void testUNSAT(final String... cryptarithms) throws CryptaModelException, CryptaSolverException {
+        for (String cryptarithm : cryptarithms) {
+            assertEquals("solution count " + cryptarithm, 0, testSolve(cryptarithm, false));
+        }
     }
 
-    public void testUNIQUE(final String cryptarithm) throws CryptaModelException, CryptaSolverException {
-        testSAT(cryptarithm, 1);
+    public void testUNIQUE(final String... cryptarithms) throws CryptaModelException, CryptaSolverException {
+        for (String cryptarithm : cryptarithms) {
+            testSAT(cryptarithm, 1);
+        }
     }
 
-    public void testNotUNIQUE(final String cryptarithm) throws CryptaModelException, CryptaSolverException {
-        assertTrue("solution count " + cryptarithm, testSolve(cryptarithm, true) > 1);
+    public void testNotUNIQUE(final String... cryptarithms) throws CryptaModelException, CryptaSolverException {
+        for (String cryptarithm : cryptarithms) {
+            assertTrue("solution count " + cryptarithm, testSolve(cryptarithm, true) > 1);
+        }
     }
 
-    public void testResource(String resourcePath)
+    public void testResource(final String resourcePath)
             throws CryptaParserException, CryptaModelException, CryptaSolverException {
         final InputStream in = getClass().getClassLoader().getResourceAsStream(resourcePath);
         final Scanner s = new Scanner(in);
@@ -178,38 +184,11 @@ public void testSendMoreMoney3() throws CryptaParserException, CryptaModelExcept
     }
 
     @Test
-    public void testSendMoreMoney4() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.testUNIQUE(" -send -more= -money");
-    }
-
-    @Test
-    public void testSendMoreMoney5() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.testUNIQUE(" (-send) + (-more) = (-money)");
-    }
-
-    @Test
-    public void testSendMoreMoney6() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.testUNIQUE("(-(-send)) + (-(-more)) = (-(-money))");
-    }
-
-    @Test
-    public void testSendMoreMoney7() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.testUNIQUE("(-send) - more = -money");
-    }
-
-    @Test
-    public void testSendMoreMoney8() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.testUNIQUE("(-(-send)) - (-more) = money");
-    }
-
-    @Test
-    public void testSendMoreMoney9() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.testUNIQUE("(send+more=money)");
-    }
-
-    @Test
-    public void testSendMoreMoney10() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.testUNIQUE("(((send+more)=(money)))");
+    public void testSendMoreMoneyParenthesis()
+            throws CryptaParserException, CryptaModelException, CryptaSolverException {
+        t.testUNIQUE(" -send -more= -money", " (-send) + (-more) = (-money)", "(-(-send)) + (-(-more)) = (-(-money))",
+                "(-send) - more = -money", "(-(-send)) - (-more) = money", "(send+more=money)",
+                "(((send+more)=(money)))");
     }
 
     @Test
@@ -510,21 +489,10 @@ public void testSendMoreMoneyList3() throws CryptaParserException, CryptaModelEx
     }
 
     @Test
-    public void testSendMoreMoneyList4() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money; s+e=n");
-    }
-
-    @Test
-    public void testSendMoreMoneyList5() throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money;;; s+e=n");
-    }
-
-    @Test
-    public void testSendMoreMoneyList6() throws CryptaParserException, CryptaModelException, CryptaSolverException {
+    public void testUnsatSendMoreMoneyList() throws CryptaParserException, CryptaModelException, CryptaSolverException {
         t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money; s+e=n;");
+        t.testUNSAT("send+more=money; s+e=n", "send+more=money;;; s+e=n", "send+more=money; s+e=n;",
+                "send+more=money&& s+e=n", "send+more=money&&&&&& s+e=n", "send+more=money&& s+e=n&&");
     }
 
     // Long multiplication with integer
@@ -532,37 +500,19 @@ public void testSendMoreMoneyList6() throws CryptaParserException, CryptaModelEx
      * SEE * SO = MIMEO MIMEO = EMOO + 10*MESS SEE * O = EMOO SEE * S = MESS
      */
     @Test
-    public void testEvaluationLongMultiplication1()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "SEE * SO = MIMEO; MIMEO = EMOO + '10'*MESS;SEE * O = EMOO;SEE * S = MESS";
-        t.testUNIQUE(cryptarithm);
-    }
+    public void testUniqueLongMultiplications() throws CryptaModelException, CryptaSolverException {
+        String[] cryptarithms = {"SEE * SO = MIMEO; MIMEO = EMOO + '10'*MESS;SEE * O = EMOO;SEE * S = MESS",
+                "SEE * SO = MIMEO; MIMEO = EMOO + \"10\"*MESS;SEE * O = EMOO;SEE * S = MESS",
+                "CUT * T = BUST; CUT * I = TNNT; TNNT * '10' + BUST = TENET; TENET = CUT * IT",
+                "RED * S = ARCS; RED * A = RED; RED * '10' + ARCS = CDTS; CDTS = RED * AS",
+                "HOW * E = HAIL; HOW * W = PAL; HAIL + PAL * '10' = LHAL; HOW * WE = LHAL",
+                "SEE * SO = MIMEO&& MIMEO = EMOO + '10'*MESS&&SEE * O = EMOO&&SEE * S = MESS",
+                "CUT * T = BUST&& CUT * I = TNNT&& TNNT * '10' + BUST = TENET&& TENET = CUT * IT",
+                "RED * S = ARCS&& RED * A = RED&& RED * '10' + ARCS = CDTS&& CDTS = RED * AS",
+                "HOW * E = HAIL&& HOW * W = PAL&& HAIL + PAL * '10' = LHAL&& HOW * WE = LHAL"
 
-    @Test
-    public void testEvaluationLongMultiplication1doubleticks()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "SEE * SO = MIMEO; MIMEO = EMOO + \"10\"*MESS;SEE * O = EMOO;SEE * S = MESS";
-        t.testUNIQUE(cryptarithm);
-    }
-
-    /*
-     * C U T I T --------- B U S T T N N T ----------- T E N E T
-     */
-    @Test
-    public void testEvaluationLongMultiplication2()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "CUT * T = BUST; CUT * I = TNNT; TNNT * '10' + BUST = TENET; TENET = CUT * IT";
-        t.testUNIQUE(cryptarithm);
-    }
-
-    /*
-     * R E D A S --------- A R C S R E D --------- C D T S
-     */
-    @Test
-    public void testEvaluationLongMultiplication3()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "RED * S = ARCS; RED * A = RED; RED * '10' + ARCS = CDTS; CDTS = RED * AS";
-        t.testUNIQUE(cryptarithm);
+        };
+        t.testUNIQUE(cryptarithms);
     }
 
     @Test
@@ -572,16 +522,6 @@ public void testEvaluationLongMultiplicationFail3()
         t.testUNSAT(cryptarithm);
     }
 
-    /*
-     * H O W W E --------- H A I L P A L --------- L H A L
-     */
-    @Test
-    public void testEvaluationLongMultiplication4()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "HOW * E = HAIL; HOW * W = PAL; HAIL + PAL * '10' = LHAL; HOW * WE = LHAL";
-        t.testUNIQUE(cryptarithm);
-    }
-
     // LONG DIVISION
     /*
      * K M ----------- A K A / D A D D Y D Y N A ----------- A R M Y A R K A
@@ -670,50 +610,8 @@ public void testSendMoreMoneyList3symbol()
         t.testSAT("send+more=money&& a+b=c");
     }
 
-    @Test
-    public void testSendMoreMoneyList4symbol()
-            throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money&& s+e=n");
-    }
-
-    @Test
-    public void testSendMoreMoneyList5symbol()
-            throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money&&&&&& s+e=n");
-    }
-
-    @Test
-    public void testSendMoreMoneyList6symbol()
-            throws CryptaParserException, CryptaModelException, CryptaSolverException {
-        t.config.setHornerScheme(true);
-        t.testUNSAT("send+more=money&& s+e=n&&");
-    }
-
     // Long multiplication with integer
 
-    @Test
-    public void testEvaluationLongMultiplication1symbol()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "SEE * SO = MIMEO&& MIMEO = EMOO + '10'*MESS&&SEE * O = EMOO&&SEE * S = MESS";
-        t.testUNIQUE(cryptarithm);
-    }
-
-    @Test
-    public void testEvaluationLongMultiplication2symbol()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "CUT * T = BUST&& CUT * I = TNNT&& TNNT * '10' + BUST = TENET&& TENET = CUT * IT";
-        t.testUNIQUE(cryptarithm);
-    }
-
-    @Test
-    public void testEvaluationLongMultiplication3symbol()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "RED * S = ARCS&& RED * A = RED&& RED * '10' + ARCS = CDTS&& CDTS = RED * AS";
-        t.testUNIQUE(cryptarithm);
-    }
-
     @Test
     public void testEvaluationLongMultiplicationFail3symbol()
             throws CryptaParserException, CryptaSolverException, CryptaModelException {
@@ -721,13 +619,6 @@ public void testEvaluationLongMultiplicationFail3symbol()
         t.testUNSAT(cryptarithm);
     }
 
-    @Test
-    public void testEvaluationLongMultiplication4symbol()
-            throws CryptaParserException, CryptaSolverException, CryptaModelException {
-        var cryptarithm = "HOW * E = HAIL&& HOW * W = PAL&& HAIL + PAL * '10' = LHAL&& HOW * WE = LHAL";
-        t.testUNIQUE(cryptarithm);
-    }
-
     // LONG DIVISION
 
     @Test