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Does this make sense?

  1. Dec 14, 2006 #1
    In predicate logic

    Let R = Run towards

    a=Adam
    b=Betty
    c=Celsi

    Would a formula like Rabc make sense?

    What would it read?

    Would Rabc = Rab & Rac
     
  2. jcsd
  3. Dec 15, 2006 #2
    if b and c are in the same location then it makes sense, but otherwise it doesnt.
    an example of three place predicate is "between", x is between y and z, here you can't divide it into Bxy&Bxz cause it doesnt make sense.
     
  4. Dec 15, 2006 #3
    b could be north of a and c is north east of a. Then a could be running towards both of them without b and c both in the same location.


    So if B is between

    then you could have Bxyz (i.e. a forumla with 3 subjects) which translates to x is between y and z. In this case it is necessary to have three subjects after B, anything else won't make sense.
     
    Last edited: Dec 15, 2006
  5. Dec 15, 2006 #4
    Is it true that in general if Rabc

    than it can be read (a R b and c)

    i.e Adam 'is running towards' Betty and Celsi.

    Adam 'is in between' Betty and Celso.
     
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