formal-methods

There does not seem to be an agreed standard for panic and log messages in Rust, and we already have quite a few inconsistencies within our code base.

I suggest we pick a format and try to stick to it; for instance, this is the closest I could find to a style guide for error messages:
https://docs.rs/serde/1.0.126/serde/de/trait.Error.html#tymethod.custom

The message should not be capital

Recent versions of TLC come with a (simple) REPL. It would be great if the REPL was integrated into the VSCode terminal.

markus@avocado:/opt/toolbox$ java -cp tla2tools.jar tlc2.REPL
Welcome to the TLA+ REPL!
TLC2 Version 2.16 of Day Month 20??
Enter a constant-level TLA+ expression.
(tla+) TRUE
TRUE