def test_expr(): assert repr(expr('P <=> Q(1)')) == '(P <=> Q(1))' assert repr(expr('P & Q | ~R(x, F(x))')) == '((P & Q) | ~R(x, F(x)))' assert (expr_handle_infix_ops('P & Q ==> R & ~S') == "P & Q |'==>'| R & ~S")