let S be non empty non void ManySortedSign ; for A being non-empty MSAlgebra over S
for C being MSCongruence of A holds C is ManySortedSubset of [| the Sorts of A, the Sorts of A|]
let A be non-empty MSAlgebra over S; for C being MSCongruence of A holds C is ManySortedSubset of [| the Sorts of A, the Sorts of A|]
let C be MSCongruence of A; C is ManySortedSubset of [| the Sorts of A, the Sorts of A|]
set SF = the Sorts of A;
let i be object ; PBOOLE:def 2,PBOOLE:def 18 ( not i in the carrier of S or C . i c= [| the Sorts of A, the Sorts of A|] . i )
assume A1:
i in the carrier of S
; C . i c= [| the Sorts of A, the Sorts of A|] . i
C . i is Relation of ( the Sorts of A . i),( the Sorts of A . i)
by A1, MSUALG_4:def 1;
then
C . i c= [:( the Sorts of A . i),( the Sorts of A . i):]
;
hence
C . i c= [| the Sorts of A, the Sorts of A|] . i
by A1, PBOOLE:def 16; verum