Introduction to Logic

Exercise 2.3 - Sorority World

Consider a variation of the Sorority World example in which we have a single binary relation, called younger. younger differs from likes in three ways. It is irreflexive, i.e. a person cannot be younger than herself. It is asymmetric, i.e. if one person is younger than a second person, then the second person is not younger than the first. It is transitive, i.e. if one person is younger than a second and the second is younger than a third, then the first is younger than the third. The table on the left below illustrates the younger relation in tabular form, and the dataset on the right shows the corresponding information as sentential data. You can click on the squares in the table to check or uncheck those squares, and the dataset on the right changes accordingly. Your mission is to change the table on the left so that it satisfies the irreflexivity, asymmetry, and transitivity of the younger relation and so that the maximum number of younger facts are true. Note that there are multiple ways in which this can be done.

  Abby Bess Cody Dana
Abby        
Bess        
Cody        
Dana