Yes, this is a typo in the original which we cannot edit at the moment. About half the time the comma will be there.
adolygu - revising, reviewing (studying for an exam)
golygu - editing (reviewing, correcting before publication)
This is a British vs. North American English thing. I've only ever seen "revise" used to mean "editing (reviewing, correcting before publication)". (Though it suggests something deeper than the word "edit" - producing a new draft, rather than making minor changes to an existing one.)