Stretto entries — interval-pattern preservation and clash detection

A stretto (overlapping subject entries) must preserve the subject's own melodic interval pattern at each entry — a 'false' or broken stretto, where the overlap departs from the subject's pattern partway through, should be an explicit authorial choice, not an unintended breakdown. Additionally, wherever stretto voices overlap, the SAME voice-leading rules apply to the resulting simultaneities — stretto does not suspend ordinary voice-leading, it adds the constraint that both voices are also independently constrained to the subject's shape.

A stretto entry matching the subject's interval pattern for its first 3 notes and then diverging without being marked as a deliberate 'free' stretto — reads as sloppy part-writing rather than the intended strict overlap.

Standard fugue pedagogy (stretto technique as taught in fugue-writing courses); not Gould/Read/Ross/Stone.

This rule needs the notated content and the rendered result together — the score says what should happen, the page says whether it did.