Theorem Subgroup.relIndex_eq_two_iff

Modification history

2026-04-27 20:25
Mathlib/GroupTheory/Index.lean
chore: Rename Xor' to Xor (#37628) …
Modified Subgroup.relIndex_eq_two_iffView on Github →
2025-10-22 18:34
Mathlib/GroupTheory/Index.lean
feat(GroupTheory/Index): criteria for subgroup to have index 2 (#30466) …
Added Subgroup.relIndex_eq_two_iffView on Github →