The sign condition determines whether or not the algebraic value of an arithmetic expression is less than, greater than, or
equal to zero. The general format for a sign condition is as follows:

- When used, "NOT" and the next keyword specify one sign condition that defines that algebraic test to be executed for truth value; for example, "NOT ZERO" is a truth test for a nonzero (positive or negative) value. An operand is positive if its value is greater than zero, negative if its value is less than zero, and zero if its value is equal to zero. The arithmetic expression must contain at least one reference to a variable.
- ZEROS or ZEROES can be used instead of ZERO in a sign test.