dom (cD (f,h)) = (dom (Shift (f,(((2 * (1. F)) ") * h)))) /\ (dom (Shift (f,(- (((2 * (1. F)) ") * h))))) by VFUNCT_1:def 2
.= the carrier of V /\ (dom (Shift (f,(- (((2 * (1. F)) ") * h))))) by FUNCT_2:def 1
.= the carrier of V /\ the carrier of V by FUNCT_2:def 1
.= the carrier of V ;
hence cD (f,h) is quasi_total by FUNCT_2:def 1; :: thesis: verum