MSAlgebra(# the Sorts of B, the Charact of B #) is MSSubAlgebra of B by MSUALG_2:37;
then A1: MSAlgebra(# the Sorts of B, the Charact of B #) is MSSubAlgebra of A by MSUALG_2:6;
B is MSSubAlgebra of MSAlgebra(# the Sorts of B, the Charact of B #) by Th17;
hence not SuperAlgebraSet B is empty by A1, Def2; :: thesis: verum