Loading
Progresso di Studio
Across all your exams
Taught in English
Questo esame si sostiene in inglese: le lezioni e le domande sono in inglese. L'interfaccia resta in italiano.
Drag to pan · ⌘/Ctrl + scroll or pinch to zoom · tap a node for detail · +/− to expand a branch
Key formulas
Contrapositive
Converse Fallacy
De Morgan's Laws
Disjunctive Syllogism
Necessary vs Sufficient
Part 1 of 3
From P → Q, only one inference is always valid:
Two fallacies that are NOT valid:
Worked example
"If R&D increases, profit margin expands." Contrapositive (valid): If profit margin did NOT expand → R&D did NOT increase. Converse (trap): If profit margin expanded → R&D increased. This does NOT follow — other things could cause profit growth. Inverse (trap): If R&D did not increase → profit margin won't expand. Also doesn't follow.
Study assistant
Paid students only — a preview
Why is this the correct answer?
Eliminate any option that contradicts something stated directly in the lesson, then check which one actually follows from the rule you just learned. Tell me which option confused you and I'll point to the exact line.
Exam strategy
If you can explain why the wrong answers are wrong, you know the topic. Remembering the right one only gets you halfway.
Unlock AI tutoring for this exam →