set S = the non void Signature;
set A = the feasible MSAlgebra over the non void Signature;
take the feasible MSAlgebra over the non void Signature ; :: thesis: ex S being non void Signature st the feasible MSAlgebra over the non void Signature is feasible MSAlgebra over S
take the non void Signature ; :: thesis: the feasible MSAlgebra over the non void Signature is feasible MSAlgebra over the non void Signature
thus the feasible MSAlgebra over the non void Signature is feasible MSAlgebra over the non void Signature ; :: thesis: verum