reserve A,B,p,q,r,s for Element of LTLB_WFF,
  i,j,k,n for Element of NAT,
  X for Subset of LTLB_WFF,
  f,f1 for FinSequence of LTLB_WFF,
  g for Function of LTLB_WFF,BOOLEAN;

theorem Th11: (con <*A*>)/.(len con <*A*>) = A
  proof
    set f = <*A*>;
A1: len f = 1 by FINSEQ_1:39;
   thus kon(f) = (con f)/.(len f) by Def2
    .= f/.1 by Th6,A1
    .= A by FINSEQ_4:16;
  end;
