\begin{definition}[Definition:Retract (Topology)/Absolute]
Let $T_1 = \struct {S_1, \tau_1}$ be a topological space.
Let $T_2 = \struct {S_2, \tau_2}$ be a topological subspace of $T_1$.
Let $T_2$ be a '''retract''' of $T_1$.
$T_2$ is an '''absolute retract''' of $T_1$ {{iff}}:
:for every closed subspace $B$ of a $T_4$ space $T$ such that $B$ is homeomorphic to $A$, then $B$ is a '''retract''' of $T$.
\end{definition}