Greetings committee! In [proposal #638](https://github.com/ghc-proposals/ghc-proposals/pull/638), @int-index proposes that we introduce a prefix form of MkSolo#, and apparent oversight in proposal #475 [Non-punning list and tuple syntax]( https://github.com/ghc-proposals/ghc-proposals/pull/475). Previously, you would write `(# a #)` to construct a `Solo# a`. But the question is: what would be the prefix form of this constructor? It can't be `(# #)`, because this is already defined as a constructor of `Unit#`! This amendment proposes the `MkSolo#` constructor, having us write `MkSolo# a` for the prefix form. The discussion seems unanimous, after care was taken to clarify that a fully applied `MkSolo# a` would still be pretty printed as `(# a #)`, avoiding programmer confusion. It seems quite straightforward to me, so: I recommend accepting this amendment to #475. -- -- Matthías Páll Gissurarson http://mpg.is/