reserve A,B,C,D,p,q,r for Element of LTLB_WFF,
        F,G,X for Subset of LTLB_WFF,
        M for LTLModel,
        i,j,n for Element of NAT,
        f,f1,f2,g for FinSequence of LTLB_WFF;

theorem th264p:
  'G' {}LTLB_WFF = {}LTLB_WFF
 proof
   thus 'G' {}LTLB_WFF c= {}LTLB_WFF
   proof
     let x be object;
     assume x in 'G' {}LTLB_WFF;then
     consider A such that
A1:  x = 'G' A & A in {}LTLB_WFF;
     thus x in {}LTLB_WFF by A1;
   end;
   thus {}LTLB_WFF c= 'G' {}LTLB_WFF;
 end;
