reserve i for Nat, x,y for set;
reserve S for non empty non void ManySortedSign;
reserve X for non-empty ManySortedSet of S;

theorem Th20:
  for a1,a2,a3,a4,a5,a6,a7,a8 being object holds
  rng <*a1,a2,a3,a4,a5,a6,a7,a8*> = {a1,a2,a3,a4,a5,a6,a7,a8}
  proof
    let a1,a2,a3,a4,a5,a6,a7,a8 be object;
    thus rng <*a1,a2,a3,a4,a5,a6,a7,a8*>
    = rng <*a1,a2,a3,a4,a5*> \/ rng <*a6,a7,a8*> by FINSEQ_1:31
    .= {a1,a2,a3,a4,a5} \/ rng <*a6,a7,a8*> by CIRCCMB3:14
    .= {a1,a2,a3,a4,a5} \/ {a6,a7,a8} by FINSEQ_2:128
    .= {a1,a2,a3,a4,a5,a6,a7,a8} by ENUMSET1:26;
  end;
