How to Prove A v C in Symbolic Logic?

[questiongirl111]

The question asks you to prove A v C

This is what I have. Everything is correct until the last question, #11

1. A V C
2. ~BvC
3.(new subproof) B
4. (new subproof ~B
5. contradiction contradiction intro 4,3
(end subproof from 4-5)
6. ~BvC V Intro 2
(end subproof from 3-6)
7. (new subproof) A
8. A v B vINTRO 1
(end subproof from 7-8)

9.(new subproof) C
10. ~BvC (vINTRO 2)
(end subproof 9-10)
11.A v C VINTRO ?


Thanks!
-J

 

[eraemia]

What class is this for? What does vINTRO mean?