Theorem Subgroup.relindex_adjoinNegOne_eq_two

Modification history

2025-11-28 11:46
Mathlib/NumberTheory/ModularForms/ArithmeticSubgroups.lean
feat(NumberTheory/ModularForms): adjoin -1 to a subgroup (#30649) …
Added Subgroup.relindex_adjoinNegOne_eq_twoView on Github →