Due Thursday, 24 January, in class.

This assignment consists of problems from Chapter 0 and problem A, below.

p 18: #1, 2 (give a formula for the deformation retraction), 3, 9, 10, 14

A. Let \( X, Y \) be CW complexes with \( A \) a subcomplex of \( Y \). Given a homotopy \(F: A \times [0,1] \to X \) between gluing maps \( f,g: A \to X \), prove that \( X\sqcup_F \left(Y \times [0,1] \right) \) deformation retracts onto \( X \sqcup_f Y \).