I'm having a hard time with logic homework. i don't comprehend when i read the instructions in a book . the assignment is to finish this argument by utilizing inference rules . so i need to set up a truth table to figure how to do that ,right? this is the problem thus far.
c: d

! : ~g -> (a v b )
2: ~b
3: a -> d
4. ( ~g )

5: ( a v b) 1, 4 mp
6: a 2, 5 ds
7: d 3,6 mp (qed)
ok she gave me this and i know modus poen
dysjunction syllogism at least what they are anyway.
and of course we do the rest. this friend of mine knows how to do them but she didn't explain what she's working from to get the answers. my question is, is she just getting the answers by a truth table that has to be set up to a certain degree? or how is she doing it? by the way, logic is the course which is not in the selection below. i should also say she gave me the solution to this but she didn't tell me how to get it?