let GF be non empty right_complementable well-unital distributive Abelian add-associative right_zeroed associative doubleLoopStr ; :: thesis: for M being non empty right_complementable vector-distributive scalar-distributive scalar-associative scalar-unital Abelian add-associative right_zeroed ModuleStr over GF holds LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #) is 1_Lattice
let M be non empty right_complementable vector-distributive scalar-distributive scalar-associative scalar-unital Abelian add-associative right_zeroed ModuleStr over GF; :: thesis: LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #) is 1_Lattice
set S = LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #);
ex C being Element of LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #) st
for A being Element of LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #) holds
( C "\/" A = C & A "\/" C = C )
proof
consider W9 being strict Subspace of M such that
A1: the carrier of W9 = the carrier of ((Omega). M) ;
reconsider C = W9 as Element of LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #) by Def3;
take C ; :: thesis: for A being Element of LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #) holds
( C "\/" A = C & A "\/" C = C )

let A be Element of LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #); :: thesis: ( C "\/" A = C & A "\/" C = C )
consider W being strict Subspace of M such that
A2: W = A by Def3;
A3: C is Subspace of (Omega). M by Lm6;
thus C "\/" A = (SubJoin M) . (C,A) by LATTICES:def 1
.= W9 + W by A2, Def7
.= ((Omega). M) + W by A1, Lm5
.= ModuleStr(# the carrier of M, the addF of M, the ZeroF of M, the lmult of M #) by Th11
.= C by A1, A3, VECTSP_4:31 ; :: thesis: A "\/" C = C
thus A "\/" C = (SubJoin M) . (A,C) by LATTICES:def 1
.= W + W9 by A2, Def7
.= W + ((Omega). M) by A1, Lm5
.= ModuleStr(# the carrier of M, the addF of M, the ZeroF of M, the lmult of M #) by Th11
.= C by A1, A3, VECTSP_4:31 ; :: thesis: verum
end;
hence LattStr(# (Subspaces M),(SubJoin M),(SubMeet M) #) is 1_Lattice by Th57, LATTICES:def 14; :: thesis: verum