Initial work on combinatorial models of GATs#135

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kris-brown wants to merge 4 commits intomainfrom combinatorial

+2,247-26

Commits on Dec 23, 2023

initial combinatorial work
Kris Brown
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better coverage
Kris Brown
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Commits on Dec 24, 2023

type/term iterator, homsearch assign whole terms, pushouts,
Kris Brown
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Commits on Dec 29, 2023

more colimits
Kris Brown
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