let V be RealLinearSpace; :: thesis: for V1 being Subset of V st V1 <> {} & V1 is linearly-closed holds
0. V in V1
let V1 be Subset of V; :: thesis: ( V1 <> {} & V1 is linearly-closed implies 0. V in V1 )
assume that
A1: V1 <> {} and
A2: V1 is linearly-closed ; :: thesis: 0. V in V1
set x = the Element of V1;
reconsider x = the Element of V1 as Element of V by A1, TARSKI:def 3;
0 * x in V1 by A1, A2;
hence 0. V in V1 by RLVECT_1:10; :: thesis: verum