mathlib3

78a08ebc - feat(data/mllist): monadic lazy lists (#865)

feat(data/mllist): monadic lazy lists (#865) * feat(data/mllist): monadic lazy lists * oops, fix header * shove into tactic namespace * make mllist into a monad (#880) * make mllist into a monad * looks good. add `take`, and some tests * update authors * cleanup test