Monday, 17 March 2014 23:36

Disjunction and Conjunction

By  Gideon
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Now suppose we consider only animals that are either duck-billed, or are mammals. 

This is the set "A or B," the disjunction of A and B, written as:

\[ A \cup B,\]

and illustrated in the following diagram:


This set, \( A \cup B,\) contains ducklings, and rabbits, and platypuses. 

On the other hand, the set of animals that are both duck-billed and are mammals is the set:

"A and B,"


\[ A \cap B,\]

and called the conjuction of A and B.



Note that the set \( A \cap B\) contains only platypuses.


Read 1491 times Last modified on Monday, 17 March 2014 23:56
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