The Arrow class as originally defined by John Hughes had methods arr, >>> and first. (>>> has since been moved by #1773 to the Category class.) When writing the "Fun of Programming" paper, I added pure as a synonym for arr, because Richard Bird preferred it. However this name hasn't caught on, and now it clashes with a method in the Applicative class, so I propose to remove it. The usual practice would be to deprecate the name in one release and remove it in the following one, but I propose to remove it in one step because * no-one seems to be using this name, and * backward compatibility has been broken anyway by the Category split (#1773). The only people who will be bitten by the change are those who import Control.Arrow hiding pure, and they wouldn't be warned by deprecation.