qiskit/qasm/qasmparser.py
def p_expression_0(self, program):
        """
        expression : expression '*' expression
                    | expression '/' expression
                    | expression '+' expression
                    | expression '-' expression
                    | expression '^' expression
        """
        program[0] = node.BinaryOp([node.BinaryOperator(program[2]),
                                    program[1], program[3]])
def p_expression_0(self, program):
        """
        expression : expression '*' expression
                    | expression '/' expression
                    | expression '+' expression
                    | expression '-' expression
                    | expression '^' expression
        """
        program[0] = node.BinaryOp([node.BinaryOperator(program[2]),
                                    program[1], program[3]])
def p_expression_0 ( self , program ) : program [ 0 ] = node . BinaryOp ( [ node . BinaryOperator ( program [ 2 ] ) , program [ 1 ] , program [ 3 ] ] )
expression : expression '*' expression
                    | expression '/' expression
                    | expression '+' expression
                    | expression '-' expression
                    | expression '^' expression
expression : expression * expression | expression / expression | expression + expression | expression - expression | expression ^ expression