When it comes to choosing operators and predicates for CAMEX , a week's experience has hardly produced a definitive list; moreover there is a certain expectation that individual users of CAMEX will generate their own. This, of course, will lead to a proliferation of nonstandard variants, but so far that hasn't happened, even for the C programs.
Part of the need for something like REC comes from the proliferation of options in a program, and in finding some way to deal with them. Considering only LCAU 's main screen, there is the full 64-neighborhood rule to be dealt with, then totalistic rules, product rules, and several kinds of reversible rules. Besides that, there is a collection of demonstration rules intended to show the user something of the variety which is possible, not to mention having selected them in advance for their attractiveness.