let R be Ring; for V being RightMod of R
for v1, v2 being Vector of V
for f being Function of V,R holds f (#) <*v1,v2*> = <*(v1 * (f . v1)),(v2 * (f . v2))*>
let V be RightMod of R; for v1, v2 being Vector of V
for f being Function of V,R holds f (#) <*v1,v2*> = <*(v1 * (f . v1)),(v2 * (f . v2))*>
let v1, v2 be Vector of V; for f being Function of V,R holds f (#) <*v1,v2*> = <*(v1 * (f . v1)),(v2 * (f . v2))*>
let f be Function of V,R; f (#) <*v1,v2*> = <*(v1 * (f . v1)),(v2 * (f . v2))*>
A1: len (f (#) <*v1,v2*>) =
len <*v1,v2*>
by Def6
.=
2
by FINSEQ_1:44
;
then A2:
dom (f (#) <*v1,v2*>) = {1,2}
by FINSEQ_1:2, FINSEQ_1:def 3;
2 in {1,2}
by TARSKI:def 2;
then A3: (f (#) <*v1,v2*>) . 2 =
(<*v1,v2*> /. 2) * (f . (<*v1,v2*> /. 2))
by A2, Def6
.=
v2 * (f . (<*v1,v2*> /. 2))
by FINSEQ_4:17
.=
v2 * (f . v2)
by FINSEQ_4:17
;
1 in {1,2}
by TARSKI:def 2;
then (f (#) <*v1,v2*>) . 1 =
(<*v1,v2*> /. 1) * (f . (<*v1,v2*> /. 1))
by A2, Def6
.=
v1 * (f . (<*v1,v2*> /. 1))
by FINSEQ_4:17
.=
v1 * (f . v1)
by FINSEQ_4:17
;
hence
f (#) <*v1,v2*> = <*(v1 * (f . v1)),(v2 * (f . v2))*>
by A1, A3, FINSEQ_1:44; verum