Dear all, Vlad proposes to change the order of implicit quantification for type variables occurring as type operators or in multiplicity annotations: https://github.com/ghc-proposals/ghc-proposals/pull/640 https://github.com/int-index/ghc-proposals/blob/int-index/tyop-quantificatio... The proposal is thankfully very simple. Change the implicit quantification order for "a `op` b" from "forall op a b" to "forall a op b". and "a %m -> b" from "forall a b m" to "forall a m b". The proposed new behavior corresponds to the original paper and our user guide. This can be considered a bug fix and while we could also just change the specification I think having a simple and memorable rule for quantification order is valuable. Especially the currently implemented quantification order for multiplicities is weird. The only painful point here is as usual a question of stability. What I don’t like about this change is, that if any code base uses it (which Vlad doubts and I tend to agree), the type error on GHC upgrade will be very incomprehensible for users who didn’t read and understand the changelog. However multiplicities are new and explicitely unstable and I don’t really see a reason why anyone would use infix notation on a qantified function. So I agree that this very unlikely to happen in the wild. Also, users who rely on the type application order right now should have noticed that something is off. Thus I recommend acceptance as is. Please voice your opinions! Malte