reserve i, i1, i2, j, j1, j2, k, m, n, t for Nat,
  D for non empty Subset of TOP-REAL 2,
  E for compact non vertical non horizontal Subset of TOP-REAL 2,
  C for compact connected non vertical non horizontal Subset of TOP-REAL 2,
  G for Go-board,
  p, q, x for Point of TOP-REAL 2,
  r, s for Real;

theorem
  width Gauge(D,n) = 2|^n + 3
proof
  thus width Gauge(D,n) = len Gauge(D,n) by JORDAN8:def 1
    .= 2|^n + 3 by JORDAN8:def 1;
end;
