reconsider rr = 1 + 1 as Element of COMPLEX by XCMPLX_0:def 2;
reconsider e3 = ((1_ F_Complex) + (1_ F_Complex)) + (1_ F_Complex) as Element of F_Complex ;
let M be Matrix of COMPLEX; :: thesis: (M + M) + M = 3 * M
A1: ( len M = len (COMPLEX2Field M) & width M = width (COMPLEX2Field M) ) ;
A2: (1_ F_Complex) + (1_ F_Complex) = the addF of F_Complex . ((1_ F_Complex),(1_ F_Complex)) by RLVECT_1:2
.= addcomplex . (1r,1r) by COMPLFLD:8, COMPLFLD:def 1
.= 1 + 1 by BINOP_2:def 3, COMPLEX1:def 4 ;
((1_ F_Complex) + (1_ F_Complex)) + (1_ F_Complex) = the addF of F_Complex . (((1_ F_Complex) + (1_ F_Complex)),(1_ F_Complex)) by RLVECT_1:2
.= addcomplex . ((1 + 1),1) by A2, COMPLFLD:def 1
.= rr + 1 by BINOP_2:def 3
.= 3 ;
then 3 * M = Field2COMPLEX (e3 * (COMPLEX2Field M)) by Def7
.= Field2COMPLEX (((1_ F_Complex) * (COMPLEX2Field M)) + (((1_ F_Complex) + (1_ F_Complex)) * (COMPLEX2Field M))) by Th12
.= Field2COMPLEX ((COMPLEX2Field M) + (((1_ F_Complex) + (1_ F_Complex)) * (COMPLEX2Field M))) by Th9
.= Field2COMPLEX ((COMPLEX2Field M) + (((1_ F_Complex) * (COMPLEX2Field M)) + ((1_ F_Complex) * (COMPLEX2Field M)))) by Th12
.= Field2COMPLEX ((COMPLEX2Field M) + ((COMPLEX2Field M) + ((1_ F_Complex) * (COMPLEX2Field M)))) by Th9
.= Field2COMPLEX ((COMPLEX2Field M) + ((COMPLEX2Field M) + (COMPLEX2Field M))) by Th9
.= Field2COMPLEX (((COMPLEX2Field M) + (COMPLEX2Field M)) + (COMPLEX2Field M)) by A1, MATRIX_3:3 ;
hence (M + M) + M = 3 * M ; :: thesis: verum