# absolute retract

A topological space $X$ is an absolute retract if, for every embedding of $X$ as a closed subset of a normal space $Y$, the image of $X$ is a retract of $Y$.

A topological space $X$ is an if, for every embedding of $X$ as a closed subset of a normal space $Y$, the image of $X$ is a neighborhood retract of $Y$.

Title absolute retract AbsoluteRetract 2013-03-22 14:39:35 2013-03-22 14:39:35 rspuzio (6075) rspuzio (6075) 5 rspuzio (6075) Definition msc 54A99 absolute neighborhood retract