 reserve i,n for Nat;
 reserve r for Real;
 reserve ra for Element of F_Real;
 reserve a,b,c for non zero Element of F_Real;
 reserve u,v for Element of TOP-REAL 3;
 reserve p1 for FinSequence of (1-tuples_on REAL);
 reserve pf,uf for FinSequence of F_Real;
 reserve N for Matrix of 3,F_Real;
 reserve K for Field;
 reserve k for Element of K;

theorem Th11:
  |[1,0,0]| is non zero &
  |[0,1,0]| is non zero &
  |[0,0,1]| is non zero &
  |[1,1,1]| is non zero by EUCLID_5:4,FINSEQ_1:78;
