mathlib

7c8dc2ad - feat(category_theory/limits): construct equalizers from pullbacks and products (#2124)

feat(category_theory/limits): construct equalizers from pullbacks and products (#2124) * construct equalizers from pullbacks and products * ... * changes from review * Add docstrings * golf proofs a little * linter Co-authored-by: Scott Morrison <scott@tqft.net> Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>