reserve a, b for Real,
  r for Real,
  rr for Real,
  i, j, n for Nat,
  M for non empty MetrSpace,
  p, q, s for Point of TOP-REAL 2,
  e for Point of Euclid 2,
  w for Point of Euclid n,
  z for Point of M,
  A, B for Subset of TOP-REAL n,
  P for Subset of TOP-REAL 2,
  D for non empty Subset of TOP-REAL 2;
reserve a, b for Real;
reserve a, b for Real;

theorem Th14:
  for a, r being Real holds r > 0 implies a in ].a-r,a+r.[
proof
  let a, r be Real;
  assume r > 0;
  then |.a-a.| < r by ABSVALUE:def 1;
  hence thesis by RCOMP_1:1;
end;
