Strong deformation retracts: local context

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

fully proved6Proved, and every prerequisite is fully proved too.

graph LR n0["Strong deformation retracts"]:::fully_proved n1["A standard simplex strongly deformation retracts onto its zero horn"]:::fully_proved n2["Good pairs and neighborhood deformation retracts"]:::fully_proved n3("The ordinary neighborhood-retract Mayer–Vietoris sequence"):::fully_proved n4["A regular neighborhood strongly deformation retracts onto its subcomplex"]:::fully_proved n5("A nonempty coproduct of pointed good pairs is good"):::fully_proved n2 --> n5 n0 --> n4 n0 --> n5 n0 --> n1 n0 --> n3 n0 --> n2 class n0 focus click n0 "../../../../../../roadmap/homology/simplicial-and-singular/relative-homology/good-pair-quotient/index.html#strong-deformation-retract" "Strong deformation retracts — 1 item · 1 fully proved" click n1 "../../../../../../roadmap/homology/computations-and-applications/post-excision-applications/index.html#standard-simplex-zero-horn-retraction" "A standard simplex strongly deformation retracts onto its zero horn — 1 item · 1 fully proved" click n2 "../../../../../../roadmap/homology/simplicial-and-singular/relative-homology/good-pair-quotient/index.html#good-pair-data" "Good pairs and neighborhood deformation retracts — 1 item · 1 fully proved" click n3 "../../../../../../roadmap/homology/computations-and-applications/sphere-homology/index.html#ordinary-neighborhood-mayer-vietoris" "The ordinary neighborhood-retract Mayer–Vietoris sequence — 1 item · 1 fully proved" click n4 "../../../../../../roadmap/homology/computations-and-applications/post-excision-applications/cw-subcomplex-neighborhood/index.html#regular-neighborhood-strong-deformation-retract" "A regular neighborhood strongly deformation retracts onto its subcomplex — 1 item · 1 fully proved" click n5 "../../../../../../roadmap/homology/computations-and-applications/post-excision-applications/index.html#sigma-good-pair" "A nonempty coproduct of pointed good pairs is good — 1 item · 1 fully proved"