feat(Combinatorics/SimpleGraph/Sum): add homomorphism, embedding and isomorphism of sums

[IvanRenison]

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[github-actions]

PR summary 6a7332dd00

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

+ Embedding.sum
+ Embedding.sum_comp_sumAssoc
+ Embedding.sum_comp_sumComm
+ Embedding.toHom_sum
+ Hom.sum
+ Hom.sum_comp_sumAssoc
+ Hom.sum_comp_sumComm
+ Iso.sumCongr
+ Iso.sumCongr_comp_sumAssoc
+ Iso.sumCongr_comp_sumComm
+ Iso.toEmbedding_sumCongr
+ Iso.toHom_sumCongr

You can run this locally as follows

## 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>

The doc-module for scripts/pr_summary/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

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

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[mkaratarakis]

Thanks! @YaelDillies could take a look please?

[YaelDillies]

I'm tempted to call these sumMap to distinguish from the similar operations based on Sum.elim.

Could you also show these commute (in the appropriate sense) with Equiv.sumComm,
Equiv.sumAssoc?

[IvanRenison]

@YaelDillies you mean that they commute with Iso.sumComm and Iso.sumAssoc?

[YaelDillies]

Something like that, yes

[IvanRenison]

I did it, although I'm not sure about the names