Perhaps somebody knowledgeable in algebraic topology could check whether
this edit changing "(S^2) v (S^3)" to "$S^2\times S^3$" at the end of the first paragraph was correct or whether it changed meaning of the post. The relevant part now reads: "to the $4$-skeleton of $S^2\times S^3$, which is $S^2\times S^3$".
(This is a restatement of a question asked on the Mathematics.SE, where the solutions were a bit disappointing. I'm hoping that professional mathematicians here might have a better solution.)
What are some problems in pure mathematics that require(d) solution techniques from the broadest and ...
