Let V be a real unitary space. A real unitary space is said to be a subspace of V if it satisfies the conditions (Def. 1). (Def. 1)(i) The carrier of it ⊆ the carrier of V , (ii) the zero of it = the zero of V , (iii) the addition of it = (the addition of V )↾[: the carrier of it, the carrier of it :], (iv) the external multiplication of it = (the external multiplication of V )↾[: R, the carrie...