Section 1
Compatibility uses the same engine as a single-person reading
A pair reading is two single-person readings joined at the resonance band. We run the four-system engine on each person independently, then look at the produced spines against each other. The intersections that name a friction or an opposition on a single chart are the same names a pair compatibility reading uses for cross-chart friction.
This is the answer to a frequent question: does my Myers-Briggs type clash with my partner’s Sun sign? It depends on the single-chart intersection table. If the chart-type intersection fires a named friction, the answer is “yes, by structure, under shared conditions”. If not, no engine-named friction is produced, and the prose can talk about whatever else it finds.
The engine doesn’t claim MBTI equals astrology, and it doesn’t claim the two systems agree all the time. It claims they call the same move by different names when they happen to. A compatibility reading uses those calls to produce the report.