Question on rules of inference

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Homework Statement


What rule of inference is used with the following statement:
Kangaroos live in Australia and are marsupials. Therefore, kangaroos are marsupials.

I set this up as p = kangaroos live in Australia and q = kangaroos are marsupials. Therefore, p. To me, it looks like the "simplification" rule, but in our book, simplification is set up as:
p ^ q; therefore, p. Can I change how I defined p and q or am I wrong to begin with?
 
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cue928 said:

Homework Statement


What rule of inference is used with the following statement:
Kangaroos live in Australia and are marsupials. Therefore, kangaroos are marsupials.

I set this up as p = kangaroos live in Australia and q = kangaroos are marsupials. Therefore, p.
Therefore q.
cue928 said:
To me, it looks like the "simplification" rule, but in our book, simplification is set up as:
p ^ q; therefore, p. Can I change how I defined p and q or am I wrong to begin with?
If your hypothesis is p ^ q, the conclusion can be p or it can be q.

IOW,
p ^ q ==> q
and
p ^ q ==> p