let X be Complex_Banach_Algebra; for w, z being Element of X holds
( (z ExpSeq) . 0 = 1. X & (Expan (0,z,w)) . 0 = 1. X )
let w, z be Element of X; ( (z ExpSeq) . 0 = 1. X & (Expan (0,z,w)) . 0 = 1. X )
thus (z ExpSeq) . 0 =
(1r / (0 !)) * (z #N 0)
by Def1
.=
(1r / (0 !)) * ((z GeoSeq) . 0)
by CLOPBAN3:def 8
.=
1r * (1. X)
by CLOPBAN3:def 7, SIN_COS:1
.=
1. X
by CLVECT_1:def 5
; (Expan (0,z,w)) . 0 = 1. X
A1:
0 -' 0 = 0
by XREAL_1:232;
hence (Expan (0,z,w)) . 0 =
(((Coef 0) . 0) * (z #N 0)) * (w #N 0)
by Def2
.=
((1r / (1r * 1r)) * (z #N 0)) * (w #N 0)
by A1, COMPLEX1:def 4, SIN_COS:1, SIN_COS:def 6
.=
(z #N 0) * (w #N 0)
by CLVECT_1:def 5, COMPLEX1:def 4
.=
((z GeoSeq) . 0) * (w #N 0)
by CLOPBAN3:def 8
.=
((z GeoSeq) . 0) * ((w GeoSeq) . 0)
by CLOPBAN3:def 8
.=
(1. X) * ((w GeoSeq) . 0)
by CLOPBAN3:def 7
.=
(1. X) * (1. X)
by CLOPBAN3:def 7
.=
1. X
by VECTSP_1:def 4
;
verum