EntityQ2141963· pop 10· linked from 79 articlesretractSign in to savecontinuous mapping from a topological space into a subspace that preserves the position of all points in that subspaceConnectionshomotopyEntityElsevierEntitycontractible spaceEntitypathologicalEntityInternational Standard Book NumberEntityfunctionEntitytopologyEntitydigital object identifierEntitycontinuous functionEntityJSTOREntitytopological spaceEntitysurjective functionEntityhomeomorphismEntityCambridge University PressEntityballEntityif and only ifEntityconvex setEntityJohn MilnorEntityconstant functionEntityidentity functionEntityCategoriesTopology