[Haskell-cafe] Functional dependence nightmare

Stephen Tetley stephen.tetley at gmail.com
Sat Mar 26 16:13:56 CET 2011

For the specific error at line 265 I think you should be using
ScopedTypeVariables and properly qualifying the type signature at the
function level with a forall.

The local annotation { ::(SubUnit a)=> } is presumably introducing
another type variable unrelated to 'a' in the function level type

Note, my suggestion is "by eye" -  I haven't run the code, so it may
not work or there may be other errors.

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