reserve 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,
  i, j, m, n for Nat,
  p for Point of TOP-REAL 2;

theorem
  for f be FinSequence st len f >= 1 holds Center f <= len f
proof
  let f be FinSequence;
  assume len f >= 1;
  then 0 + len f < len f + len f by XREAL_1:6;
  then len f+1 <= 2*len f by NAT_1:13;
  then (len f+1+1) div 2 <= len f by NAT_2:25;
  then (len f+(1+1)) div 2 <= len f;
  then len f div 2+1 <= len f by NAT_2:14;
  hence thesis by JORDAN1A:def 1;
end;
