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 th265:
  F |= A & (for B st B in F holds {}LTLB_WFF |=0 B)
    implies {}LTLB_WFF |=0 A
proof
  assume
Z1: F |= A & (for B st B in F holds {}LTLB_WFF |=0 B);then
  for B st B in F holds {}LTLB_WFF |= B by th262b,th264p;
  hence {}LTLB_WFF |=0 A by th262b,th264p,th218,Z1;
end;
