title: how to use z3 in python to solve smt question
body: <p>I have some problem in using python's package z3 to solve some smt question</p>
  <p>my teacher told me to input: z3 km_test.smt in terminal of pycharm,but I received :</p>
  <p>usage: z3 [-h] [--s3-prefix S3_PREFIX] [--filesystem FILESYSTEM] [--snapshot-prefix SNAPSHOT_PREFIX] {backup,restore,status} ...
  z3: error: argument subcommand: invalid choice: 'km_test.smt' (choose from 'backup', 'restore', 'status')</p>
  <p>who can answer me how to deal with this problem.</p>