mathlib3

8943351e - feat(topology/algebra/module): define `fst` and `snd`, review (#2247)

feat(topology/algebra/module): define `fst` and `snd`, review (#2247) * feat(topology/algebra/module): define `fst` and `snd`, review * Fix compile Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>