let R be Ring; VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is strict LeftMod of strict
set a = 0. Trivial-addLoopStr ;
set G = VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #);
A1:
for a, b being Element of
for x, y being Element of st x = a & b = y holds
a + b = x + y
;
A2:
( VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is Abelian & VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is add-associative & VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is right_zeroed & VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is right_complementable )
proof
thus
VectSpStr(# 1,
op2 ,
op0 ,
(pr2 the carrier of R,1) #) is
Abelian
( VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is add-associative & VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is right_zeroed & VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is right_complementable )
let a be
Element of ;
ALGSTR_0:def 16 a is right_complementable
reconsider x =
a as
Element of ;
consider b being
Element of
such that A3:
x + b = 0. Trivial-addLoopStr
by ALGSTR_0:def 11;
reconsider b' =
b as
Element of ;
take
b'
;
ALGSTR_0:def 11 a + b' = 0. VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #)
thus
a + b' = 0. VectSpStr(# 1,
op2 ,
op0 ,
(pr2 the carrier of R,1) #)
by A3;
verum
end;
hence
VectSpStr(# 1,op2 ,op0 ,(pr2 the carrier of R,1) #) is strict LeftMod of strict
by A2, VECTSP_1:def 26; verum