let a1, a2, a3, a4, a5, b1, b2, b3, b4, b5 be Complex; <*a1,a2,a3,a4,a5*> + <*b1,b2,b3,b4,b5*> = <*(a1 + b1),(a2 + b2),(a3 + b3),(a4 + b4),(a5 + b5)*>
A1:
<*a1,a2,a3,a4*> + <*b1,b2,b3,b4*> = <*(a1 + b1),(a2 + b2),(a3 + b3),(a4 + b4)*>
by FINSEQ_9:43;
( <*a1,a2,a3,a4,a5*> = <*a1,a2,a3,a4*> ^ <*a5*> & <*b1,b2,b3,b4,b5*> = <*b1,b2,b3,b4*> ^ <*b5*> )
by FINSEQ_4:75;
then <*a1,a2,a3,a4,a5*> + <*b1,b2,b3,b4,b5*> =
<*(a1 + b1),(a2 + b2),(a3 + b3),(a4 + b4)*> ^ <*(a5 + b5)*>
by A1, FINSEQ_9:40
.=
<*(a1 + b1),(a2 + b2),(a3 + b3),(a4 + b4),(a5 + b5)*>
by FINSEQ_4:75
;
hence
<*a1,a2,a3,a4,a5*> + <*b1,b2,b3,b4,b5*> = <*(a1 + b1),(a2 + b2),(a3 + b3),(a4 + b4),(a5 + b5)*>
; verum