GRAMMAR

aexp    false / true / int / real / string / (exp,...) / [exp,...] / name / fun name...->exp
appexp  aexp... aexp
infexp  appexp [name infexp]
exp     if exp (| pat -> exp)
        if exp then exp else exp
        let name name... = exp in exp
        __op (int name...)... in exp
        letrec (name name... = exp);... in exp
        infexp
apat    false / true / int / real / string / (exp,...) / [exp,...] / name
pat     apat[:pat]

OPERATORS

LEVEL	LEFT	RIGHT

9   |                   |
8   |   * / rem ++      |
7   |   + -             |   :
6   |   == /= <= >= < > |   
5   |                   |   and or
4   |                   |
3   |                   |
2   |                   |
1   |   >>              |   <<