#15316: Regarding coherence and implication loops in presence of QuantifiedConstraints -------------------------------------+------------------------------------- Reporter: mniip | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.5 checker) | Keywords: Resolution: | QuantifiedConstraints Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by mniip): Replying to [comment:3 simonpj]:
This leads to a question: should forall c. c => c be an inferrable local axiom schema in absence of UndecidableInstances?
I think not. I'm busy adding a check for this case! Agreed?
What kind of check? Just for the `c => c` case? Are you sure there aren't any roundabout ways to achieve similar `fix id`-type corecursion? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15316#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler