> I wonder what the meaning of "+-++-10" would be? :-) That's traditional when writing grammars for math expressions. Unary + is a no-op, unary - is a negation, and if they're stacked the result is the same as if parens had been used. In other words, the meaning of the above is "10" since the two -'s cancel each other -- just as if you'd written +(-(=(=(-(10))))).
Almost nobody takes advantage of this... but there seems to be no reason to forbid it. (Remember, this isn't a C-based language, so ++ and -- don't have special meaning.) ______________________________________ Joe Kesselman / IBM Research
