reserve Al for QC-alphabet;
reserve i,j,n,k,l for Nat;
reserve a for set;
reserve T,S,X,Y for Subset of CQC-WFF(Al);
reserve p,q,r,t,F,H,G for Element of CQC-WFF(Al);
reserve s for QC-formula of Al;
reserve x,y for bound_QC-variable of Al;

theorem
  Proof_Step_Kinds is finite
  proof
    Proof_Step_Kinds = succ Segm 9 by NAT_1:54;
   hence thesis;
  end;
