Unary "-" performs arithmetic negation if the operand is numeric.  If the operand is an identifier, a string con-
sisting of a minus sign concatenated with the identifier is returned.  Otherwise, if the string starts with a plus
or minus, a string starting with the opposite sign is returned.  One effect of these rules is that "-bareword" is
equivalent to "-bareword".

##</code><code>##

If you don't want it to test the right operand
till the next evaluation, as in sed, just use three dots ("...") instead of two.  In all other regards, "..."
behaves just like ".." does.