Model returns unknown stability result

[hallba]

Due to a bug in Z3 4.5.0 the attached model returns unknown stability result

BugSmaller.zip

The bug has been fixed in the latest master (Z3Prover/z3#991). The included Z3 should be updated to fix the issue

[hallba]

A different model (by @trinjacky) raises an unknown stability result due to a Z3 bug, and has fixed in a recent update (see Z3Prover/z3#1217) . Updating the packaged Z3 to the latest version should fix both issues