{"id":{"repo_id":"stellenbosch","oai_identifier":"oai:scholar.sun.ac.za:10019.1/135773"},"canonical_url":"https://search.dev.ndltd.org/etd/stellenbosch/oai:scholar.sun.ac.za:10019.1/135773","repository":{"repo_id":"stellenbosch","name":"Stellenbosch University","base_url":"https://scholar.sun.ac.za/server/oai/request"},"display":{"title":"Extensivity relative to a bifunctor","abstract":"Extensive categories capture a fundamental feature of the category of sets: their coproducts are both disjoint and universal. Two equivalent formulations of extensive categories provide two distinct perspectives on the notion. The first is as a property of functors, and the second as a property of morphisms in the category. This thesis explores both perspectives. The morphism-focused viewpoint is captured through extensive morphisms, which allow one to study extensivity in categories that are not themselves extensive. 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Near-sums provide a natural setting for extending the theory of extensive categories, capturing key features thereof, such as disjointness and universality.","abstract_has_math":false,"creators":["Theart, Emma"],"institution":"Stellenbosch : Stellenbosch University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Hoefnagel, Michael"],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026-03","date_published":"2026-03","updated_at":"2026-07-24T04:40:14Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholar.sun.ac.za/handle/10019.1/135773","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Hoefnagel, Michael"]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Stellenbosch University. 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