public void can_parse_mathematical_set_constraints(string input, int actual, int first, int last, bool expected)
        {
            var result = NumericalConstraintParser.GetParser(ec => actual, ec => first, ec => last).Parse(input);

            Assert.Equal(expected, result(new ExecutionContext()));
        }
        public void cannot_parse_invalid_input(string input)
        {
            var result = NumericalConstraintParser.GetParser(ec => 0, ec => 0, ec => 0)(new Input(input));

            Assert.False(result.WasSuccessful && result.Remainder.AtEnd);
        }