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
  for a1,a2,a3,a4,a5,a6,a7 being object holds
  rng <*a1,a2,a3,a4,a5,a6,a7*> = {a1,a2,a3,a4,a5,a6,a7}
  proof
    let a1,a2,a3,a4,a5,a6,a7 be object;
    thus rng <*a1,a2,a3,a4,a5,a6,a7*>
    = rng <*a1,a2,a3,a4,a5*> \/ rng <*a6,a7*> by FINSEQ_1:31
    .= {a1,a2,a3,a4,a5} \/ rng <*a6,a7*> by CIRCCMB3:14
    .= {a1,a2,a3,a4,a5} \/ {a6,a7} by FINSEQ_2:127
    .= {a1,a2,a3,a4,a5,a6,a7} by ENUMSET1:20;
  end;
