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sunday_seriftoday at 3:54 AM0 repliesview on HN

For me, proof by contradiction only clicked (recently!) once I understood that logical consequence and unsatisfiability are equivalent.

Once I understood that and reframed the contradiction as a statement about unsatisfiability… I could then see directly how the positive result you get is the equivalent logical consequence.

Unfortunately, I feel like this intuition only really helps if you are pretty immersed in formal logic… otherwise it just sounds like jibberish.