let S be non empty non void ManySortedSign ; :: thesis: for A being non-empty MSAlgebra of S
for R being invariant ManySortedRelation of A holds InvCl R = R
let A be non-empty MSAlgebra of S; :: thesis: for R being invariant ManySortedRelation of A holds InvCl R = R
let R be invariant ManySortedRelation of A; :: thesis: InvCl R = R
thus ( InvCl R c= R & R c= InvCl R ) by Def11; :: according to PBOOLE:def 10 :: thesis: verum