The ‾ (negative) operator takes one number, variable, or expression and negates its value, thus returning the negative equivalent of it. The ‾ operator appears higher in the order of operations than both the relational and logical operators, so it will be executed first. In addition, it has the same order of operation as the other math operators, so the calculator simply executes them left to right in the order that they appear.
:‾1 -1 :5→X :‾3(X+2 -21 :‾2→A:‾3→B :AB 6
When adding a negative number to a positive number, switch the two numbers around and change the addition to subtraction. This allows you to get rid of the ‾ sign and save a byte.
:‾A+B→C can be :B-A→C
This is not always the case, however: if you subtract a command that uses a lot of parentheses and is followed by a newline/colon/STO→ arrow, it'd save space to put the subtraction at the beginning of the line. For instance:
:inString(Ans,sub(Str1,1,1+int(log(A))))-1 can be :‾1+inString(Ans,sub(Str1,1,1+int(log(A
If an ERR:SYNTAX is being thrown near a subtraction or negation where there should be no errors, check to make sure that ‾ (negation) and - (subtraction) were not swapped by mistake.