[Haskell] Syntax Q: How do you share RHS's in case expressions!?

I'm baffled that I can't find anywhere in the documentation how to associate two or more patterns with the same right-hand-side... For example, in OCaml: match 3 with 3 -> 99 | 4 -> 99 Can be abbreviated match 3 with 3 | 4 -> 99 But I have had no luck figuring out how to do the same thing with: case 3 of 3 -> 99; 4 -> 99 My apologies if the answer to this question is blindingly obvious! --Ryan