Idempotent
Part of speech: adjective
Definition: Describing an action which, when performed multiple times, has no further effect on its subject after the first time it is performed.
Unchanged
Part of speech: adjective
Definition: not changed or altered; remaining in an original state
Example sentence: In the practical world of computing, it is rather uncommon that a program, once it performs correctly and satisfactorily, remains unchanged forever.
