PROBLEM 1
1. A -->(B-->C)
2 |(A-->(D&(E&B))) ACP
3 || A ACP
4 ||B-->C ->E 1,2
5 ||D&(E&B) ->E 2,3
6 || E&B &E5
7 || B &E6
8 || C ->E 4,7
9 | A-->C ->I 3-8
10 (A-->(D&(E&B)))-->(A-->C) ->I 2-9
PROBLEM 2
1 A-->B
2 ~A-->~C
3 |C ACP
4 || ~A ACP
5 || ~C -> E 2,4
6 || ⊥ ⊥I 3, 5
7 |A ~I
8 C --> A ->I 3-7
9 | C ACP
10| A ->E 8,9
11| B ->E 1, 10
__________________
12 C -->B ->I 9-11
PROBLEM 3
1 C v ~C
2 C --> ~B
3 ~C --> ~N
4| C ACP
5| ~B ->E 2,4
6| ~Bv~N vI 5
7 C --> (~Bv~N) ->I 4-6
8| ~C ACP
9| ~N ->E 3,8
10| ~Bv~N vI 9
11 ~C --> (~Bv~N) ->I 8-10
__________________________
12 ~Bv~N vE 1, 7, 11
PROBLEM 4: This is not a valid argument. Might you have typed it incorrectly?
F-->(GvH)
G
_________
F-->H