set M = the rmult of V;
set W = RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #);
A1:
RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) is RightMod-like
A2:
for a, b being Element of
for x, y being Vector of st x = a & b = y holds
a + b = x + y
;
( RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) is Abelian & RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) is add-associative & RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) is right_zeroed & RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) is right_complementable )
proof
thus
RightModStr(# the
carrier of
V,the
addF of
V,
(0. V),the
rmult of
V #) is
Abelian
( RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) is add-associative & RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) is right_zeroed & RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) is right_complementable )
let a be
Element of ;
ALGSTR_0:def 16 a is right_complementable
reconsider x =
a as
Vector of ;
reconsider b =
(comp V) . x as
Element of ;
take
b
;
ALGSTR_0:def 11 a + b = 0. RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #)
thus a + b =
x + (- x)
by VECTSP_1:def 25
.=
0. RightModStr(# the
carrier of
V,the
addF of
V,
(0. V),the
rmult of
V #)
by RLVECT_1:16
;
verum
end;
then reconsider W = RightModStr(# the carrier of V,the addF of V,(0. V),the rmult of V #) as RightMod of by A1;
A3:
( 0. W = 0. V & the addF of W = the addF of V || the carrier of W )
by RELSET_1:34;
the rmult of W = the rmult of V | [:the carrier of W,the carrier of R:]
by RELSET_1:34;
then reconsider W = W as Submodule of V by A3, Def2;
take
W
; W is strict
thus
W is strict
; verum