Is the principle of equivalence a principle?

摘要

The work argues the principle of equivalence to be a theorem and not aprinciple (in a sense of an axiom). It contains a detailed analysis of theconcepts of normal and inertial frame of reference. The equivalence principleis proved to be valid (at every point and along every path) in anygravitational theory based on linear connections. Possible generalizations ofthe equivalence principle are pointed out.