IBM SC34-5764-01 Manuel d'utilisateur Page 171

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NOP
Purpose
 NOP ; 
NOP is a dummy instruction that has no effect. It can be useful as the target of a THEN or ELSE clause:
Example:
Select
when a=c then nop /* Do nothing */
when a>c then say 'A > C'
otherwise say 'A < C'
end
Note: Putting an extra semicolon instead of the NOP would merely insert a null clause, which would be
ignored. The second WHEN clause would be seen as the first instruction expected after the THEN,
and would, therefore, be treated as a syntax error. NOP is a true instruction, however, and is,
therefore, a valid target for the THEN clause.
NOP
Chapter 13. Keyword Instructions 149
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