ABAP Keyword Documentation →  ABAP − Reference →  Program Flow Logic →  Expressions and Functions for Conditions →  log_exp - Logical Expressions →  log_exp - Boolean Operators and Parentheses → 

log_exp - NOT

Syntax

... NOT log_exp ...

Effect

The negation of a logical expression log_exp using NOT creates a new logical expression that is false if the logical expression log_exp is true and vice versa.

Notes

... NOT operand NOT IN seltab ...
The first NOT is a Boolean operator that negates a comparison expression. The second NOT is a part of the comparison expression withe the relational operator IN. This is made clear using parentheses around the comparison expression:
... NOT ( operand NOT IN seltab ) ...