let X, Y, Z be RealLinearSpace; 0. (R_VectorSpace_of_BilinearOperators (X,Y,Z)) = the carrier of [:X,Y:] --> (0. Z)
A1:
0. (RealVectSpace ( the carrier of [:X,Y:],Z)) = the carrier of [:X,Y:] --> (0. Z)
;
R_VectorSpace_of_BilinearOperators (X,Y,Z) is Subspace of RealVectSpace ( the carrier of [:X,Y:],Z)
by RSSPACE:11;
hence
0. (R_VectorSpace_of_BilinearOperators (X,Y,Z)) = the carrier of [:X,Y:] --> (0. Z)
by A1, RLSUB_1:11; verum