Added "λ" pretty printing to python (#7320)

Author: philzook58

src/api/python/z3/z3printer.py

@@ -1412,8 +1412,10 @@ def pp_quantifier(self, a, d, xs):
         ys_pp = group(seq(ys))
         if a.is_forall():
             header = "∀"
-        else:
+        elif a.is_exists():
             header = "∃"
+        else:
+            header = "λ"
         return group(compose(to_format(header, 1),
                              indent(1, compose(ys_pp, to_format(" :"), line_break(), body_pp))))