Package fortran2c;
Helpers
    digit = ['0' .. '9'];
Tokens
    number = digit+;
    double = ((digit)+ '.' (digit)*) | ((digit)* '.' (digit)+);
    plus = '+';
    minus = '-';
    mult = '*';
    div = '/';
    mod = '%';
    l_par = '(';
    r_par = ')';
    sin = 'sin';
    blank = (' ' | 13 | 10)+;
Ignored Tokens
    blank;
Productions
    expr =
        {factor} factor |
        {plus} expr plus factor |
        {minus} expr minus factor 
        ;
    factor =
        {term} term |
        {mult} factor mult term |
        {div} factor div term |
        {mod} factor mod term
        ;
    term =
        {number} number |
        {double} double |
        {expr} l_par expr r_par |
        {sine} sin l_par expr r_par
        ;