def p_bin_expressions(self, p):
"""
expression : expression PLUS expression
| expression MINUS expression
| expression TIMES expression
| expression DIVIDE expression
| expression MPLUS expression
| expression MMINUS expression
| expression MTIMES expression
| expression MDIVIDE expression
"""
p[0] = ast.BinaryExpression(p[1], p[2], p[3])
def p_relation(self, p):
"""relation : expression logic_operator expression"""
p[0] = ast.BinaryExpression(p[1], p[2], p[3])