let H, v be LTL-formula; :: thesis: for N being strict LTLnode over v st H in the LTLnew of N & ( H is atomic or H is negative ) holds
* N = * (SuccNode1 (H,N))

let N be strict LTLnode over v; :: thesis: ( H in the LTLnew of N & ( H is atomic or H is negative ) implies * N = * (SuccNode1 (H,N)) )
set N1 = SuccNode1 (H,N);
assume that
A1: H in the LTLnew of N and
A2: ( H is atomic or H is negative ) ; :: thesis: * N = * (SuccNode1 (H,N))
A3: ( not H is next & not H is Until ) by A2, MODELC_2:78;
set NX = the LTLnext of N;
set N1X = the LTLnext of (SuccNode1 (H,N));
A4: the LTLnext of (SuccNode1 (H,N)) = the LTLnext of N \/ (LTLNext H) by A1, Def4;
set NN = the LTLnew of N;
set N1N = the LTLnew of (SuccNode1 (H,N));
set NO = the LTLold of N;
set N1O = the LTLold of (SuccNode1 (H,N));
A5: the LTLold of (SuccNode1 (H,N)) = the LTLold of N \/ {H} by A1, Def4;
A6: not H is Release by A2, MODELC_2:78;
A7: ( not H is conjunctive & not H is disjunctive ) by A2, MODELC_2:78;
then A8: LTLNew1 H = {} by A3, A6, Def1;
A9: the LTLnew of (SuccNode1 (H,N)) = ( the LTLnew of N \ {H}) \/ ((LTLNew1 H) \ the LTLold of N) by A1, Def4;
A10: for a being object st a in the LTLold of (SuccNode1 (H,N)) \/ the LTLnew of (SuccNode1 (H,N)) holds
a in the LTLold of N \/ the LTLnew of N
proof
let a be object ; :: thesis: ( a in the LTLold of (SuccNode1 (H,N)) \/ the LTLnew of (SuccNode1 (H,N)) implies a in the LTLold of N \/ the LTLnew of N )
assume A11: a in the LTLold of (SuccNode1 (H,N)) \/ the LTLnew of (SuccNode1 (H,N)) ; :: thesis: a in the LTLold of N \/ the LTLnew of N
( not a in the LTLold of (SuccNode1 (H,N)) or a in the LTLold of N or a in {H} ) by A5, XBOOLE_0:def 3;
then A12: ( not a in the LTLold of (SuccNode1 (H,N)) or a in the LTLold of N or a in the LTLnew of N ) by A1, TARSKI:def 1;
( a in the LTLnew of (SuccNode1 (H,N)) implies ( a in the LTLnew of N & not a in {H} ) ) by A8, A9, XBOOLE_0:def 5;
hence a in the LTLold of N \/ the LTLnew of N by A11, A12, XBOOLE_0:def 3; :: thesis: verum
end;
A13: for a being object st a in the LTLold of N \/ the LTLnew of N holds
a in the LTLold of (SuccNode1 (H,N)) \/ the LTLnew of (SuccNode1 (H,N))
proof
let a be object ; :: thesis: ( a in the LTLold of N \/ the LTLnew of N implies a in the LTLold of (SuccNode1 (H,N)) \/ the LTLnew of (SuccNode1 (H,N)) )
assume A14: a in the LTLold of N \/ the LTLnew of N ; :: thesis: a in the LTLold of (SuccNode1 (H,N)) \/ the LTLnew of (SuccNode1 (H,N))
( not a in the LTLnew of N or ( not a in {H} & a in the LTLnew of N ) or ( a in {H} & a in the LTLnew of N ) ) ;
then A15: ( not a in the LTLnew of N or a in the LTLnew of N \ {H} or a in the LTLold of N \/ {H} ) by XBOOLE_0:def 3, XBOOLE_0:def 5;
( a in the LTLold of N implies a in the LTLold of (SuccNode1 (H,N)) ) by A5, XBOOLE_0:def 3;
hence a in the LTLold of (SuccNode1 (H,N)) \/ the LTLnew of (SuccNode1 (H,N)) by A8, A5, A9, A14, A15, XBOOLE_0:def 3; :: thesis: verum
end;
LTLNext H = {} by A7, A3, A6, Def3;
hence * N = * (SuccNode1 (H,N)) by A4, A10, A13, TARSKI:2; :: thesis: verum