Project-declaredLean 4.32.1
Restrict insert kpair eq restrict of not mem
LO.FirstOrder.SetTheory.restrict_insert_kpair_eq_restrict_of_not_mem
Plain-language statement
Restricting an inserted relation to a set that does not contain the inserted first coordinate recovers the original restriction.
formal logicmetatheoryproof theory
Source project: Foundation
Person-level attribution pending.