let S be non empty non void ManySortedSign ; for U0 being MSAlgebra over S
for U1, U2 being MSSubAlgebra of U0 st the Sorts of U1 = the Sorts of U2 holds
MSAlgebra(# the Sorts of U1, the Charact of U1 #) = MSAlgebra(# the Sorts of U2, the Charact of U2 #)
let U0 be MSAlgebra over S; for U1, U2 being MSSubAlgebra of U0 st the Sorts of U1 = the Sorts of U2 holds
MSAlgebra(# the Sorts of U1, the Charact of U1 #) = MSAlgebra(# the Sorts of U2, the Charact of U2 #)
let U1, U2 be MSSubAlgebra of U0; ( the Sorts of U1 = the Sorts of U2 implies MSAlgebra(# the Sorts of U1, the Charact of U1 #) = MSAlgebra(# the Sorts of U2, the Charact of U2 #) )
assume
the Sorts of U1 = the Sorts of U2
; MSAlgebra(# the Sorts of U1, the Charact of U1 #) = MSAlgebra(# the Sorts of U2, the Charact of U2 #)
then
( U1 is MSSubAlgebra of U2 & U2 is MSSubAlgebra of U1 )
by Th8;
hence
MSAlgebra(# the Sorts of U1, the Charact of U1 #) = MSAlgebra(# the Sorts of U2, the Charact of U2 #)
by Th7; verum