Since a unary minus operator can be used when no preceding mathematical operator was provided, e.g. "-1 -1" and "-1 -(1)" both resolve to -2, it follows that if the previous operand is the result of a bracket-delimited expression the same should occur, i.e. "(-1) -1" or "(-1) -(1)" should also both resolve to -2, however this case is not covered in the test suite.