On the role of the commutator algebra for nonlinear supersymmetry

We discuss a closure of commutator algebras for general functionals in terms of Nambu-Goldstone fermions and their derivative terms under nonlinear supersymmetry (NLSUSY) both in flat spacetime and in curved spacetime. We point out that variations of functionals for vector supermultiplets (uniquely) determine general LSUSY transformations for linear vector supermutiplets with general auxiliary fields in extended SUSY, where the closure of the commutator algebras for NLSUSY plays a crucial role.