Ramin Honary on Nostr: npub1gus3x…tlr07 you aren't allowed to use parentheses as operators, so <(@)> ...

npub1gus3xvh5652kmkg3n02p2n99pmduzqv656emkz2p4f3veaqlfxzqwtlr07 (npub1gus…lr07) you aren't allowed to use parentheses as operators, so <(@)> wouldn't be allowed as an infix operator operator, and the < and > symbols alone are operators returning the Bool type so the expression would not typecheck.
But it's true, Haskell one-liners can be almost as obscure as APL code at times. Unlike APL, you can actually lookup the types of each symbol and that gives you a pretty good clue as to how it works.