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PR summary 14d4247eef

Import changes for modified files

No significant changes to the import graph

## summary with just the declaration names:
./scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/pr_summary/declarations_diff.sh long <optional_commit>

./scripts/reporting/technical-debt-metrics.sh pr_summary

This pull request has conflicts, please merge master and resolve them.

At the ProofBench workshop, we came to the following conclusions:

1. It is worth having minors on SimpleGraph as data
2. It is not worth having minors on SimpleGraph as a relation
3. Instead, one should define the minor relation on Graph and convert any SimpleGraph to Graph to use the relation there

What do you think? Do you want to see our code?

Yes I would like to see what you did :-) Changing my definition of contraction to keep the map instead of an existential is rather minor, but going through Graph would be a big change...

BTW what was the rationale for not wanting the minor relation (as a preorder) on simple graphs?

The issue is basically that you can't contract triangles correctly: you should get a loop, but simple graphs are assumed loopless.

Here is what we came up with: https://gist.github.com/YaelDillies/6b5d502919c9b1736030633b0a4cacb1