#13879: Strange interaction between higher-rank kinds and type synonyms -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.1 checker) | Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"fae672f647fe00c303d8fb56971563c1a76ad04e/ghc" fae672f/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="fae672f647fe00c303d8fb56971563c1a76ad04e" Fix constraint solving for forall-types Trac #13879 showed that when we were trying to solve (forall z1 (y1::z1). ty1) ~ (forall z2 (y2:z2). ty2) we'd end up spitting out z1~z2 with no binding site for them. Those kind equalities need to be inside the implication. I ended up re-factoring the code for solving forall-equalities. It's quite nice now. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13879#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler