We prove that the q-model category of -multipointed d-spaces for is not left proper by constructing a weak equivalence whose pushout along a q-cofibration obtained by attaching a single 1-dimensional globular cell is not a weak equivalence. The counterexample is constructed in the category of -Hausdorff -generated spaces. For , all objects are automatically saturated, and for , the original weak equivalence is between saturated objects. The failure is caused by a family of nonconstant execution paths that converges in the ambient mapping space to a constant map which is not an execution path; after the globular cell is attached, this degeneration causes two previously distinct path components to merge.

生成讲解博客的中文版本

生成AI智能校验的中文版本