Theorems · Theorem · group theory

AddSubgroup.index_comap

∀ {G : Type u_1} {G' : Type u_2} [inst : AddGroup G] [inst_1 : AddGroup G'] (H : AddSubgroup G) (f : G' →+ G),
  (AddSubgroup.comap f H).index = H.relIndex f.range

Defined in

Mathlib.GroupTheory.Index

Cited by

4 results in Mathlib

Foundations

Depth 95 from the axioms · uses propext, Classical.choice, Quot.sound

Assumes

AddGroupAddGroup