In complex or contentious discussions, the central or top-level topic is often altered or replaced. We're all familiar from experience with this phenomenon. Topologically this is sort of like a wormhole:

Imagine two copies of $\mathbb{R}^3$ minus the open unit ball, glued together along the unit spheres. Imagine enclosing the origin with a sphere of radius 2. This is a topological separation: The origin is separated from the rest of your space, the copy of $\mathbb{R}^3$ that you're standing in. But, what's contained in the enclosure is an entire world just as large; therefore, the origin is not really contained, merely separated. One could walk through the enclosure, and pass through the unit ball boundary, and then proceed back out through the unit ball boundary into the other alternative copy of $\mathbb{R}^3$.

You come to a crux of the issue, or you come to a clash of discourse norms or background assumptions; and then you bloop, where now that is the primary motive or top-level criterion for the conversation.

This has pluses and minuses. You are finding out what the conversation really wanted to be, finding what you most care about here, finding out what the two of most ought to fight about / where you can best learn from each other / the highest leverage ideas to mix. On the other hand, you lose some coherence; there is disorientation; it's harder to build up a case, integrate information into single nodes for comparison; and it's harder to follow. [More theory could be done here.]

How to orient to this? Is there a way to use software to get more of the pluses and fewer of the minuses, e.g. in order to have better debates? E.g. by providing orienting structure with signposts and reminders but without clumsy artificial rigid restrictions on the transference of salience?