Re: lines/unlines and "inverse"

On Monday, 2002-07-22, 11:25, CEST, Koen Claessen wrote:

Lars Henrik Mathiesen wrote:

| lines . unlines = id | unlines . lines . unlines == unlines | words . unwords . words = words

Don't be fooled by the information content of the second equation -- the first equation directly implies it:

unlines . lines . unlines == {assoc (.)} unlines . (lines . unlines) == {equation 1} unlines . id == {id is unit of (.)} unlines

Yes, but the first equation is not true because, e.g., lines (unlines ["\n"]) = ["",""].

[...]

Wolfgang