mathlib3

a1c0ad58 - feat(category_theory): def `is_isomorphic_setoid`, `groupoid.iso_equiv_hom` (#1506)

feat(category_theory): def `is_isomorphic_setoid`, `groupoid.iso_equiv_hom` (#1506) * feat(category_theory): def `is_isomorphic_setoid`, `groupoid.iso_equiv_hom` * Move to a dedicated file, define `isomorphic_class_functor` * explicit/implicit arguments * Update src/category_theory/groupoid.lean * Update src/category_theory/groupoid.lean * Update src/category_theory/isomorphism_classes.lean * Update src/category_theory/isomorphism_classes.lean * Update src/category_theory/isomorphism_classes.lean