Talk:Mapping cylinder

Not correct

a minor point: "no two points (x,t) in X x I equivalent" is not correct if f is not injective. Thus we need a reformulation of the equivalence relation. - Saibot2 16:19, 6 February 2007 (UTC)

Deformation Retraction R

Shouldn't we have:

$([t,x],s)\mapsto [(1-s)\cdot t,x],(y,s)\mapsto y$

Or does this not matter/have I got something wrong? 2404:4408:4A1A:EE00:9CD:330C:402D:FD82 (talk) 20:43, 3 April 2024 (UTC)