LOGIC SIDECAR · VALIDITY LANE

Does it follow?

Name the kind of thing you are talking about, then three properties it can have. Two starting points share a bridge property; the conclusion links the other two. This page answers one question only — does the conclusion follow? — and shows you why on the circles. Whether the starting points are true is a different question, and it always goes to a panel.

staffing chainbroken bridgeneeds existence
…that are:
Starting point 1shiftsare
Starting point 2shiftsare
Conclusionshiftsare
re-checks on every change once all three groups are named; the button always works
1. All shifts that are understaffed are slow to triage
2. All shifts that are at night are understaffed
∴ All shifts that are at night are slow to triage
It follows — the conclusion is forced
If both starting points are true, there is no way to arrange the circles where the conclusion fails: every blue-hatched region the conclusion needs is exactly where the starting points already put things.
THE SIX CHECKS
middle term distributed at least once
no illicit major (P distributed in conclusion but not its premise)
no illicit minor (S distributed in conclusion but not its premise)
not two negative premises
a negative premise if and only if a negative conclusion
two universal premises give a universal conclusion (else holds only if the subject class is non-empty)
understaffedslow to triageat night
Gray shading = the starting points rule that region empty. × = something must live there. Blue hatching = the region the conclusion talks about.
What these starting points CAN certify: All shifts that are at night are slow to triage (current)
On the map this certifies an entails(formal) edge — provenance “computed”, zero panel votes spent. Whether the two starting points are TRUE still goes to a stratified panel.
record: figure 1 · AAA
plain sentences · dialogues