• twopi@lemmy.ca
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    5 days ago

    Your example is incorrect.

    • All cats are peanut butter (c is a subset of p)
    • some peanut butter are dogs (p intersects d, or, d is a subset of p)
    • some cats are dogs (c and d intersect, or, d is a subset of c)

    The first two do not make the third.

    You can have:

    • c is a subset of p,
    • d and p intersect,
    • The section of p that intersects with d does not contain any c

    To fix this, reverse the first statement.

    • All peanut butter are cats (p is a subset of c)
    • some peanut butter are dogs (p intersects d, or, d is a subset of p)
    • some cats are dogs (c and d intersect, or, d is a subset of c)

    Any portion of d that intersects with p (some p is d) must also be c (since all p is in c). Hence some c, but not all c, is in the portion of p that intersects with d (some c is d).

    • Zozano@aussie.zone
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      5 days ago

      Oops. I fucked up lol. I changed it with your edit :p

      Mental note: don’t do syllogisms at 1am.