LOGIC SIDECAR · VALIDITY LANE

Does it follow?

Write the argument as three plain sentences — two starting points and a conclusion. This page answers one question only: does the conclusion follow? Whether the starting points are true is a different question, and it always goes to a panel.

a chaina deniala broken bridgea shifted premise
1. All underfunded departments are overcrowded
2. Our department is overcrowded
∴ Our department is underfunded
It does not follow
“overcrowded” is the bridge between your two statements, but neither statement covers all of “overcrowded”. Two groups can each overlap a different part of “overcrowded” without ever touching each other.
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)
WHAT IT READ · read by the built-in reader
bridge: overcrowded · subject: our department · predicate: underfunded · AAA-2
overcrowdedunderfundedour department
Gray = ruled out by the starting points. Blue hatching = what the conclusion claims. If any blue survives outside the gray, the conclusion can fail.
The reading
This is how your three sentences were understood. If a term or a quantifier is wrong, change it here and re-check.
Starting point 1are
Starting point 2are
Conclusionare
Reading with the built-in pattern reader; the verdict is computed here by a fixed engine either way.
step-by-step builder · dialogues