Impreza
11-05-2003, 07:10 PM
does anyone here take or have taken phil279??
i have a couple questions, i have been trying these all last night and today but cant seem to figue it out!
1. Derive "A" from:
A v B, ~C, ~B v C
i am having trouble with the two disjunctions. I try to get "A" using negation elimination but i cant seem to get it right. PLEASE HELP!!!
2. Show that [(A > B) > A] > A is a theorem.
Ok, first, i couldlnt find the if-then conditional symbol, so i used ">", so > is the symbol for a if-then conditional. I started off this proof by assuming (A > B) > A, which i think is right, after thaty, i just got lost, i am trying to derive "A" under the main scopeline but i am having some major troubles. thx!!
ps, this is all in SD. thx!
i have a couple questions, i have been trying these all last night and today but cant seem to figue it out!
1. Derive "A" from:
A v B, ~C, ~B v C
i am having trouble with the two disjunctions. I try to get "A" using negation elimination but i cant seem to get it right. PLEASE HELP!!!
2. Show that [(A > B) > A] > A is a theorem.
Ok, first, i couldlnt find the if-then conditional symbol, so i used ">", so > is the symbol for a if-then conditional. I started off this proof by assuming (A > B) > A, which i think is right, after thaty, i just got lost, i am trying to derive "A" under the main scopeline but i am having some major troubles. thx!!
ps, this is all in SD. thx!