Modify the Hoare judgment such that is also ensures thread safity.
Before, it just ensured that whenever one can split up the memory into two parts before running the program, the framing part can be split off when the program is finished. Now it also ensure that it can be split off at any moment during the execution of the program. When we extend to non-deterministic expressions/sequence points we certainly need this for the Hoare judgment for expressions, as C allows evaluation of them to interleave. However, for consistency, and further extensions, it is nice to have this property for statements too.