Metamath Proof Explorer


Theorem ifpidg

Description: Restate wff as conditional logic operator. (Contributed by RP, 20-Apr-2020)

Ref Expression
Assertion ifpidg θif-φψχφψθφθψχφθθφχ

Proof

Step Hyp Ref Expression
1 dfifp4 if-φψχ¬φψφχ
2 1 bibi2i θif-φψχθ¬φψφχ
3 dfbi2 θ¬φψφχθ¬φψφχ¬φψφχθ
4 imor θ¬φψφχ¬θ¬φψφχ
5 ordi ¬θ¬φψφχ¬θ¬φψ¬θφχ
6 ancomst φθψθφψ
7 impexp θφψθφψ
8 imor φψ¬φψ
9 8 imbi2i θφψθ¬φψ
10 imor θ¬φψ¬θ¬φψ
11 9 10 bitri θφψ¬θ¬φψ
12 6 7 11 3bitrri ¬θ¬φψφθψ
13 imor θφχ¬θφχ
14 13 bicomi ¬θφχθφχ
15 12 14 anbi12i ¬θ¬φψ¬θφχφθψθφχ
16 4 5 15 3bitri θ¬φψφχφθψθφχ
17 8 bicomi ¬φψφψ
18 df-or φχ¬φχ
19 17 18 anbi12i ¬φψφχφψ¬φχ
20 cases2 φψ¬φχφψ¬φχ
21 20 bicomi φψ¬φχφψ¬φχ
22 19 21 bitri ¬φψφχφψ¬φχ
23 22 imbi1i ¬φψφχθφψ¬φχθ
24 jaob φψ¬φχθφψθ¬φχθ
25 ancomst ¬φχθχ¬φθ
26 pm5.6 χ¬φθχφθ
27 25 26 bitri ¬φχθχφθ
28 27 anbi2i φψθ¬φχθφψθχφθ
29 23 24 28 3bitri ¬φψφχθφψθχφθ
30 16 29 anbi12i θ¬φψφχ¬φψφχθφθψθφχφψθχφθ
31 3 30 bitri θ¬φψφχφθψθφχφψθχφθ
32 ancom φθψθφχφψθχφθφψθχφθφθψθφχ
33 an4 φψθχφθφθψθφχφψθφθψχφθθφχ
34 32 33 bitri φθψθφχφψθχφθφψθφθψχφθθφχ
35 2 31 34 3bitri θif-φψχφψθφθψχφθθφχ