Structural search does not read content. It reads the logical shape of sentences — which bits of grammar are active (agency, coupling, resolution, phase, scope, polarity) and where the sentence sits in a 49-dimensional structural subspace. Results that share no keywords with your query but appear in the Structural column have the same morphological fingerprint. These are called leapfrogs. Learn more.
Structural search finds documents built the same way — same grammar, same agency patterns — regardless of topic.
When a result appears in the Structural column but not in Semantic, you've found a leapfrog: same bureaucratic shape, completely different subject.