Identity systems of descent data for pushouts#1150
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EgbertRijke merged 3 commits intoJun 6, 2024
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This PR depends on #1148. New commits start at "Make flattening lemmas take non-dependent universal properties". |
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This PR replaces the (unfinished, non-dependent) universal property of identity types of pushouts with the induction principle, expressed as the property of being an identity system.
I show that the canonical descent data for identity types is an identity system, and that identity systems are uniquely unique.