reserve n for Nat,
  k for Integer;
reserve p for polyhedron,
  k for Integer,
  n for Nat;

theorem Th64:
  (dim(p) - 1)-polytopes(p) is non empty
proof
  set n = dim(p) - 1;
  0 - 1 = -1;
  then
A1: -1 <= n by XREAL_1:9;
  n <= dim(p) by XREAL_1:146;
  hence thesis by A1,Th23;
end;
