The strip-connected upper cover 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("Hatcher's binary cover of the strip enlargement"):::fully_proved n1("The cone-side cover member is contractible"):::fully_proved n2("The strip-connected upper cover is contractible"):::fully_proved n3("An open-cover model for attached cells"):::fully_proved n0 -.-> n3 n0 --> n2 n2 -.-> n3 n1 -.-> n2 click n0 "../../../../../../roadmap/fundamental-group/van-kampen/cell-attachment-support/auxiliary/index.html#auxiliary-cell-attachment-open-cover" "Hatcher's binary cover of the strip enlargement — 1 item · 1 fully proved" 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" class n2 focus 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/fundamental-group/van-kampen/index.html#cell-attachment-cover-model" "An open-cover model for attached cells — 1 item · 1 fully proved"