set W = RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #);
A1: for u, v, w being VECTOR of holds (u + v) + w = u + (v + w)

proof

let u, v, w be VECTOR of ; :: thesis: (u + v) + w = u + (v + w)
reconsider u' = u, v' = v, w' = w as VECTOR of ;
thus (u + v) + w = (u' + v') + w'
.= u' + (v' + w') by RLVECT_1:def 6
.= u + (v + w) ; :: thesis: verum

end;

A2: for v being VECTOR of holds v + (0. RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #)) = v

proof

let v be VECTOR of ; :: thesis: v + (0. RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #)) = v
reconsider v' = v as VECTOR of ;
thus v + (0. RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #)) = v' + (0. V)
.= v by RLVECT_1:10 ; :: thesis: verum

end;

A3: RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #) is right_complementable

proof

let v be VECTOR of ; :: according to ALGSTR_0:def 16 :: thesis: v is right_complementable
reconsider v' = v as VECTOR of ;
consider w' being VECTOR of such that
A4: v' + w' = 0. V by ALGSTR_0:def 11;
reconsider w = w' as VECTOR of ;
take w ; :: according to ALGSTR_0:def 11 :: thesis: v + w = 0. RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #)
thus v + w = 0. RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #) by A4; :: thesis: verum

end;

A5: for a being real number
for v, w being VECTOR of holds a * (v + w) = (a * v) + (a * w)

proof

let a be real number ; :: thesis: for v, w being VECTOR of holds a * (v + w) = (a * v) + (a * w)
let v, w be VECTOR of ; :: thesis: a * (v + w) = (a * v) + (a * w)
reconsider v' = v, w' = w as VECTOR of ;
thus a * (v + w) = a * (v' + w')
.= (a * v') + (a * w') by RLVECT_1:def 9
.= (a * v) + (a * w) ; :: thesis: verum

end;

A6: for a, b being real number
for v being VECTOR of holds (a * b) * v = a * (b * v)

proof

let a, b be real number ; :: thesis: for v being VECTOR of holds (a * b) * v = a * (b * v)
let v be VECTOR of ; :: thesis: (a * b) * v = a * (b * v)
reconsider v' = v as VECTOR of ;
thus (a * b) * v = (a * b) * v'
.= a * (b * v') by RLVECT_1:def 9
.= a * (b * v) ; :: thesis: verum

end;

A7: for a, b being real number
for v being VECTOR of holds (a + b) * v = (a * v) + (b * v)

proof

let a, b be real number ; :: thesis: for v being VECTOR of holds (a + b) * v = (a * v) + (b * v)
let v be VECTOR of ; :: thesis: (a + b) * v = (a * v) + (b * v)
reconsider v' = v as VECTOR of ;
thus (a + b) * v = (a + b) * v'
.= (a * v') + (b * v') by RLVECT_1:def 9
.= (a * v) + (b * v) ; :: thesis: verum

end;

A8: for a being Real
for v, w being VECTOR of
for v', w' being VECTOR of st v = v' & w = w' holds
( v + w = v' + w' & a * v = a * v' ) ;
A9: for v, w being VECTOR of holds v + w = w + v

proof

let v, w be VECTOR of ; :: thesis: v + w = w + v
reconsider v' = v, w' = w as VECTOR of ;
thus v + w = w' + v' by A8
.= w + v ; :: thesis: verum

end;

for v being VECTOR of holds 1 * v = v

proof

let v be VECTOR of ; :: thesis: 1 * v = v
reconsider v' = v as VECTOR of ;
thus 1 * v = 1 * v'
.= v by RLVECT_1:def 9 ; :: thesis: verum

end;

then reconsider W = RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #) as RealLinearSpace by A9, A1, A2, A3, A5, A7, A6, RLVECT_1:def 5, RLVECT_1:def 6, RLVECT_1:def 7, RLVECT_1:def 9;
A10: the Mult of W = the Mult of V | [:REAL ,the carrier of W:] by RELSET_1:34;
( 0. W = 0. V & the addF of W = the addF of V || the carrier of W ) by RELSET_1:34;
hence RLSStruct(# the carrier of V,the U2 of V,the addF of V,the Mult of V #) is strict Subspace of V by A10, Def2; :: thesis: verum