We establish a first-principles ontological definition of the electron within Energy-Efficiency Theory (EET). The electron is defined as an indecomposable, localized steady-state configuration of constrained-state energy, described by the constrained potential Ue(r). Its inertial mass is given by the total constrained energy: me = R UedV /c2 . The Compton wavelength λc = h/(mec) emerges as the characteristic spatial scale of the constrained potential. We distinguish the electron (constrained-state) from the photon (free-state) at the ontological level, and discuss the implications for understanding quantum particles. This work provides the rule consequent foundation for the electron in EET, complementing the natural-causal treatments of its wave-particle duality and interactions.
Hongpu Yang (Sat,) studied this question.