Question #1651

Since when do we start ignoring the contropositives?

Started by Jvsquaq1 · started 2023-10-03 16:56 · last activity 2023-10-03 20:38 · 1 reply

How and why do we ignore the contra here but not other places, rules #2 says if H is on monday N is on Friday, contrapositive would be N not on 5 then H not on 1, and in the case of wednesday H is not on 1 its on day 3? But then nancy shows up in the only possible block that is friday?

Replies

  1. Emil-Kunkin · 2023-10-03 20:38

    The contrapositive here is indeed if n not 5 then H not 1. Having n in 5 and h in 3 doesn't violate it. The rule is that if h is 1 then n must be 5, but this doesn't ban having n in 5 without H in 1. I think you may be flipping sufficient and necessary in your head, although your articulation of the rule is spot on.

Sign in to reply.