merge with master

3 jobs for luonng_variableAssignment in 2 minutes and 8 seconds (queued for 1 second)
Name Stage Failure
failed
test Test
> There were failing tests. See the report at: file:///builds/xt9634/ProofScriptParser/rt/build/reports/tests/test/index.html

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 17s
ERROR: Job failed: exit code 1