let F be Field; for S being SymSp of F
for b, a, x being Element of S
for k, l being Element of F st not a _|_ & a _|_ & a _|_ holds
k = l
let S be SymSp of F; for b, a, x being Element of S
for k, l being Element of F st not a _|_ & a _|_ & a _|_ holds
k = l
let b, a, x be Element of S; for k, l being Element of F st not a _|_ & a _|_ & a _|_ holds
k = l
let k, l be Element of F; ( not a _|_ & a _|_ & a _|_ implies k = l )
assume that
A1:
not a _|_
and
A2:
( a _|_ & a _|_ )
; k = l
set 1F = 1_ F;
a _|_
by A2, Th23;
then
a _|_
by VECTSP_1:59;
then
a _|_
by VECTSP_1:def 26;
then
a _|_
by VECTSP_1:41;
then
a _|_
by VECTSP_1:def 19;
then
a _|_
by VECTSP_1:def 26;
then
a _|_
by Def1;
then A3:
a _|_
by VECTSP_1:def 26;
assume
not k = l
; contradiction
then
k - l <> 0. F
by RLVECT_1:35;
then
a _|_
by A3, VECTSP_1:def 22;
hence
contradiction
by A1, VECTSP_1:def 26; verum