Retraction (topology)
CONTINUOUS MAPPING FROM A TOPOLOGICAL SPACE INTO A SUBSPACE
Deformation retraction; Neighborhood retract; Strong deformation retract; Absolute retract; Absolute neighborhood retract; Defamation retraction; Neighborhood deformation retract; Deformation retract; NDR-pair; No-retraction theorem; Retract (topology)
In topology, a branch of mathematics, a retraction is a continuous mapping from a topological space into a subspace that preserves the position of all points in that subspace.Borsuk (1931).