New posts in retraction

Do retracts in topology coincide with categorical retracts?

general-topology algebraic-topology retraction

Is it okay to do that with proving $\mathbb R^2$ and $\mathbb R^2 \setminus \left\{0\right\}$ are homeomorphic?

Is $S^1\vee\ldots\vee S^1$ a deformation retract of $\mathbb R^2-\{x^1,\ldots,x^n\}$?

algebraic-topology retraction