1.   P v Q
 _
|  2.   ¬Q
|  _
|  3.
|  4.
|  5.
|  6.
|  7.
|  8.   P
9.   ¬Q → P   → Intro 2-8

1.   P v Q
 _
|  2.   ¬Q --- assumed [1]
|  3.   P --- assumed [2] for v-Elim
|  4.   P --- from 3
|  5.   Q --- assumed [3] for v-Elim
|  6.   ⊥ --- from 2 and 5 by →-Elim (recall that : ¬Q is abbrev for Q → ⊥)
|  7.   P --- from 6 by ⊥-Elim
|  8.   P --- from 3-4 an 5-7 with 1 by v-Elim, discharging [2] and [3]
|  9.   ¬Q → P --- from 2 and 8 by →-Intro, discharging [1]
10.   (P v Q) → (¬Q → P)   --- from 1 and 9 by →-Intro

1.   ¬Q → P
 _
|  2.   ¬(P v Q) --- assumed [1]
|  3.   Q --- assumed [2]
|  4.   P v Q --- from 2 by v-Intro
|  5.   ⊥ --- from 2 and 4 by →-Elim (recall that : ¬A is abbrev for A → ⊥)
|  6.   ¬Q --- from 3 and 5 by →-Intro discharging [2]
|  7.   P --- from 6 and 1 by →-Elim
|  8.   P v Q --- from 7 by v-Intro
|  9.   ⊥ --- from 2 and 8 by →-Elim
|  10.  P v Q --- from 2 and 9 by RAA (or Double Negation) discharging [1]
11.   (¬Q → P) → (P v Q) --- from 1 and 10 by →-Intro