23 May
2010
23 May
'10
1:30 p.m.
On Sun, May 23, 2010 at 11:38 AM, Daniel Fischer
On Sunday 23 May 2010 18:24:50, R J wrote:
Correction: the theorem is h . either (f, g) = either (h . f, h . g)
Still not entirely true,
const True . either (undefined, undefined) $ undefined = True
while
either (const True . undefined, const True . undefined) undefined = undefined
But if we ignore bottom,
If we ignore bottom we say "By parametricity." The theorem is a free theorem.