Iof proof for Lemma sq stable and:
1. P :
2. Q :
3. (
P) 
P
4. (
Q) Q
5.
(P 
Q)
P
by ((BasicSquashHD 5)
CollapseTHEN (UnhideSinceSquashedConcl))
C1:
C1: 5. P Q
C1: P
C.| 9,38 |
P) P
Q) Q
(P Q)
P
by ((BasicSquashHD 5)
CollapseTHEN (UnhideSinceSquashedConcl))
C1:
C1: 5. P Q
C1: P
C.
| Definitions |  TT |