You're given a sentence and your task is to classify whether the sentence is acceptable or not. Any sentence which is grammatically correct, has a naturalistic text, is written by a native speaker and which minimizes superfluous content is acceptable, otherwise unacceptable. If the sentence is acceptable then write "acceptable", otherwise "unacceptable".

Bob proved that this set is recursive.
acceptable

Tom ordered bacon, and Dick lettuce, and I think that Harry tomatoes.
unacceptable

Under the bed is a fun place to hide.

acceptable