Question

One of these functions that is defined in terms of maps of a closed subcomplex of a CW-complex can always be extended to be defined in terms of maps of the entire complex. If one of these functions exists between the identity map on a space X and a constant function, then X (10[1])is contractible. (10[4])A (10[1])fibration is a map that satisfies a lifting (-5[1])property of these functions (10[1])with respect to any space. (-5[1])These functions are used to define an equivalence (10[1])relation (10[1])on loops (10[1])whose equivalence classes are members of the fundamental group. For two spaces X and Y and two functions f (10[1])and g both from X to Y, one of these functions is defined from [read slowly to end of sentence] “X cross (10[1])the closed unit interval” to Y such that it agrees with “f of x” at “x comma zero” and (-5[1])agrees with “g of x” at “x comma one.” For 10 points, name these functions that define an equivalence between topological spaces (10[1])that is weaker than the notion (-5[1])of homeomorphic spaces. (10[1]0[1])■END■ (10[1]0[8])

ANSWER: homotopies [or homotopy; accept homotopic equivalence or homotopy equivalence or homotopy equivalent; accept homotopy lifting property; accept homotopy extension property; accept null-homotopic; accept homotopy group] (The first sentence refers to the fact that CW pairs have the homotopy extension property.)
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Summary

2023 ACF Nationals04/22/2023Y2268%0%18%91.60

Buzzes

PlayerTeamOpponentBuzz PositionValue
Henry CafaroChicago CCornell B5210
Vivek SasseChicago BYale A5410
Alex LiGeorgia Tech AOhio State A5410
Max ChemtovMcGill AVirginia A5410
Isaac MammelMaryland AFlorida A5410
Swapnil GargUC Berkeley AHarvard A5510
Carlos DoebeliImperial AVanderbilt A63-5
Tim MorrisonStanford AWUSTL A6710
Conor ThompsonIowa State ARutgers A72-5
Tanis NielsenClaremont AYale B8010
Ricky LiMIT AColumbia A8110
Alex AkridgeIndiana AMinnesota A8310
Anson BernsBrown ADuke A10210
Vincent DuNorth Carolina ATexas A12410
Kevin YeUC Berkeley BMichigan A143-5
Geoffrey ChenCornell AChicago A16510
Jack ObermanSouth Carolina APenn A171-5
Raymond JiangGeorgia Tech BPenn State A17410
Joelle SmartRutgers AIowa State A1740
Forrest WeintraubColumbia BHouston A1750
John BroussardHouston AColumbia B1750
Max BrodskyIllinois AWUSTL B17510
Jonathan LauJohns Hopkins ARutgers B1750
Collin AceRutgers BJohns Hopkins A1750
Benjamin WeinerMinnesota BFlorida B1750
Jeya IyaduraiFlorida BMinnesota B1750
Anirudh BharadwajPenn ASouth Carolina A1750
James StevensonMichigan AUC Berkeley B1750