Cornelius Diekmann

``` COST CENTRE MODULE %time %alloc divmod_integer Network.IPTables.Generated 18.6 32.2 times_int Network.IPTables.Generated 12.9 15.1 minus_nat Network.IPTables.Generated 12.4 23.7 power Network.IPTables.Generated 9.3 12.2 sgn_integer Network.IPTables.Generated 5.4 0.0 equal_nat Network.IPTables.Generated 5.0 0.0...

There is too much noise in the match expressions. Just look at all those `(MatchAnd MatchAny (MatchAnd MatchAny ...` https://github.com/diekmann/Iptables_Semantics/blob/refactoring/thy/Iptables_Semantics/Primitive_Matchers/Protocols_Normalize.thy#L510

TODOs: Asses where safe versions of Isabelle-generated functions can be exported without cluttering the code with error handling. If Isabelle-generated functions are called wrongly, then this is a coding error...

Using `rewrite_Goto_safe` and `unfold_ruleset_CHAIN_safe` consistently now. - `map_of_ipassmt` may still error

Indeed, my use case in 100% contrived. Also, Terraform v0.12.0-beta2 rejects this self reference. The provided config is the simplest example I could come up with to trigger the crash....

Awesome, thanks :+1: Now a rather tough question: I can also use `-m multiport --ports 22` to match on ports and Mignis does not complain. Looking at the code, this...

> In m6 in bits 0 and 1 animated tile state is stored. Make functions do not reset those bits. Furthermore other data in m6 is stored from bit 2....

Okay, my understanding how to continue with this PR: * Remove the `REQUIRE` tests for free bits, since we cannot assume that free bits are actually initialized to 0. *...

Done. Is the change in docs/landscape_grid.html from `O` to `U` too large and controversial such that I shall move it to a standalone PR?

Done, removed [docs commit](https://github.com/OpenTTD/OpenTTD/commit/278778ee5017e771872ede649554ed9ffa6ac75f) from this PR. Updated PR description and rebased. Now it's just one unit test file. One thing at a time :smiley: