Stage 35 · Logic & Quantifiers
35.2.2 Necessary Condition
35.2 Sufficient, Necessary, and Both
Point 2 of 5
35.2.2 Necessary Condition
Core idea"Without it, nothing works": for q to hold you must first have p, q⇒p, so p is a necessary condition for q.
Module goal. Capture the relationship between hypothesis and conclusion with "is it enough to have it, can you do without it" — and learn to identify all three kinds of conditions.