Question 912745
DS stands for "Disjunctive Syllogism"


The rule is


P v Q
~P
therefore, Q


It's a fancy way of saying: "you have two options, but one of those options is taken away from you: so you're just left with one option"


--------------------------------------------------------------


Line 3 has a disjunction which is P v Q. Line 2 has the negation of P, so that forces Q to be leftover


Therefore, <font size=5 color="red">Q</font> must go in line 4. Line 5 is definitely R because that's the overall conclusion you want to get to.


Let me know if you need more help or if you need me to explain a step in more detail.
Feel free to email me at <a href="mailto:jim_thompson5910@hotmail.com?Subject=I%20Need%20Algebra%20Help">jim_thompson5910@hotmail.com</a>
or you can visit my website here: <a href="http://www.freewebs.com/jimthompson5910/home.html">http://www.freewebs.com/jimthompson5910/home.html</a>


Thanks,


Jim