[Haskell-cafe] lambda calculus and equational logic

[Richard O'Keefe]

On Jul 14, 2010, at 1:51 AM, Ben Lippmeier wrote:
> Replacing equals by equals usually doesn't change anything.
>
> What kind of equality do you use for  getChar :: IO Char ?

The usual one:  getChar = getChar.  It's a pure value.
If I find [getChar,getChar] in a program, I can safely
replace it by let g = getChar in [g,g].