[...]
The [] in the formula is spurious, and it should read <2>1. Inv /\ [Next]_vars => Inv
The [] in the formula is spurious, and it should read
<2>1. Inv /\ [Next]_vars => Inv
<2>1. Inv /\ [Next]_vars => Inv'
to make it interesting (and sufficiently strong for the following invariant proof).
Kai