Metamath Proof Explorer


Theorem pm11.71

Description: Theorem *11.71 in WhiteheadRussell p. 166. (Contributed by Andrew Salmon, 24-May-2011)

Ref Expression
Assertion pm11.71 xφyχxφψyχθxyφχψθ

Proof

Step Hyp Ref Expression
1 nfv yφψ
2 nfv xχθ
3 1 2 aaan xyφψχθxφψyχθ
4 anim12 φψχθφχψθ
5 4 2alimi xyφψχθxyφχψθ
6 3 5 sylbir xφψyχθxyφχψθ
7 nfv xχ
8 7 nfex xyχ
9 exim yφχψθyφχyψθ
10 19.42v yφχφyχ
11 19.42v yψθψyθ
12 9 10 11 3imtr3g yφχψθφyχψyθ
13 pm3.21 yχφφyχ
14 simpl ψyθψ
15 14 imim2i φyχψyθφyχψ
16 13 15 syl9 yχφyχψyθφψ
17 12 16 syl5 yχyφχψθφψ
18 8 17 alimd yχxyφχψθxφψ
19 18 adantl xφyχxyφχψθxφψ
20 ax-11 xyφχψθyxφχψθ
21 nfv yφ
22 21 nfex yxφ
23 exim xφχψθxφχxψθ
24 19.41v xφχxφχ
25 19.41v xψθxψθ
26 23 24 25 3imtr3g xφχψθxφχxψθ
27 pm3.2 xφχxφχ
28 simpr xψθθ
29 28 imim2i xφχxψθxφχθ
30 27 29 syl9 xφxφχxψθχθ
31 26 30 syl5 xφxφχψθχθ
32 22 31 alimd xφyxφχψθyχθ
33 20 32 syl5 xφxyφχψθyχθ
34 33 adantr xφyχxyφχψθyχθ
35 19 34 jcad xφyχxyφχψθxφψyχθ
36 6 35 impbid2 xφyχxφψyχθxyφχψθ