The cone-side cover member is contractible: local context

Project map · Chapter map · Full theorem DAG · Open textbook statement

This local map shows one dependency hop in either direction. The highlighted item is the current focus. What the colours mean

fully proved4Proved, and every prerequisite is fully proved too.

graph LR n0("A single cone attachment has a two-set open cover"):::fully_proved n1("The cone-side cover member is contractible"):::fully_proved n2("The strip-connected upper cover is contractible"):::fully_proved n3["Relative homology is reduced homology of the mapping cone"]:::fully_proved n0 --> n1 n1 -.-> n2 n1 -.-> n3 click n0 "../../../../../roadmap/fundamental-group/van-kampen/cell-attachment-support/index.html#single-cone-open-cover" "A single cone attachment has a two-set open cover — 1 item · 1 fully proved" class n1 focus click n1 "../../../../../roadmap/fundamental-group/van-kampen/cell-attachment-support/index.html#single-cone-upper-contractible" "The cone-side cover member is contractible — 1 item · 1 fully proved" click n2 "../../../../../roadmap/fundamental-group/van-kampen/cell-attachment-support/auxiliary/index.html#auxiliary-upper-cover-contractible" "The strip-connected upper cover is contractible — 1 item · 1 fully proved" click n3 "../../../../../roadmap/homology/computations-and-applications/post-excision-applications/index.html#mapping-cone-relative-reduced-homology" "Relative homology is reduced homology of the mapping cone — 1 item · 1 fully proved"