Theorem Subgroup.index_eq_two_iff'

Modification history

2026-04-27 20:25

Mathlib/GroupTheory/Index.lean

chore: Rename Xor' to Xor (#37628) …

Modified Subgroup.index_eq_two_iff'View on Github →

2025-10-22 18:34

Mathlib/GroupTheory/Index.lean

feat(GroupTheory/Index): criteria for subgroup to have index 2 (#30466) …

Added Subgroup.index_eq_two_iff'View on Github →