for S being non empty non void ManySortedSign
for A being non-empty MSAlgebra over S
for C being MSCongruence of A
for s being SortSymbol of S
for x, y being Element of the Sorts of A . s holds
( ((MSNat_Hom (A,C)) . s) . x = ((MSNat_Hom (A,C)) . s) . y iff [x,y] in C . s )