reserve X for set, x,y,z for object,
  k,l,n for Nat,
  r for Real;
reserve i,i0,i1,i2,i3,i4,i5,i8,i9,j for Integer;
reserve r1,p,p1,g,g1,g2 for Real,
  Y for Subset of REAL;

theorem
  [\ r /] <= [/ r \]
proof
A1: r <= [/ r \] by Def7;
  [\ r /] <= r by Def6;
  hence thesis by A1,XXREAL_0:2;
end;
