strong=weak ... lax vs strict ... flexible ... "robust vs delicate" ... ?? idea that "robust vs delicate" fits in well with whole idea of "topology as rubber sheet geometry" ???? .... ..... ????? "topology" vs "homotopy" .... progression from topology to homotopy as built into topology ... ??? analogy with category ??? .... ??? how far to push this analogy ??? ... hmmmm ... category of categories .... space of spaces .... ??? .... ?? discrete space of spaces vs interesting space of spaces .... ???? .....