Metamath Proof Explorer


Theorem bnj1204

Description: Well-founded induction. The proof has been taken from Chapter 4 of Don Monk's notes on Set Theory. See http://euclid.colorado.edu/~monkd/setth.pdf . (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

Ref Expression
Hypothesis bnj1204.1 ψyAyRx[˙y/x]˙φ
Assertion bnj1204 RFrSeAxAψφxAφ

Proof

Step Hyp Ref Expression
1 bnj1204.1 ψyAyRx[˙y/x]˙φ
2 simp1 RFrSeAxAψφxA¬φRFrSeA
3 ssrab2 xA|¬φA
4 3 a1i RFrSeAxAψφxA¬φxA|¬φA
5 simp3 RFrSeAxAψφxA¬φxA¬φ
6 rabn0 xA|¬φxA¬φ
7 5 6 sylibr RFrSeAxAψφxA¬φxA|¬φ
8 nfrab1 _xxA|¬φ
9 8 nfcrii zxA|¬φxzxA|¬φ
10 9 bnj1228 RFrSeAxA|¬φAxA|¬φxxA|¬φyxA|¬φ¬yRx
11 2 4 7 10 syl3anc RFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRx
12 biid RFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRxRFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRx
13 nfv xRFrSeA
14 nfra1 xxAψφ
15 nfre1 xxA¬φ
16 13 14 15 nf3an xRFrSeAxAψφxA¬φ
17 16 nf5ri RFrSeAxAψφxA¬φxRFrSeAxAψφxA¬φ
18 11 12 17 bnj1521 RFrSeAxAψφxA¬φxRFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRx
19 eqid xA|¬φ=xA|¬φ
20 19 12 bnj1212 RFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRxxA
21 nfra1 yyxA|¬φ¬yRx
22 simp3 yAyRxyxA|¬φ¬yRxyxA|¬φ¬yRx
23 22 bnj1211 yAyRxyxA|¬φ¬yRxyyxA|¬φ¬yRx
24 con2b yxA|¬φ¬yRxyRx¬yxA|¬φ
25 24 albii yyxA|¬φ¬yRxyyRx¬yxA|¬φ
26 23 25 sylib yAyRxyxA|¬φ¬yRxyyRx¬yxA|¬φ
27 simp2 yAyRxyxA|¬φ¬yRxyRx
28 sp yyRx¬yxA|¬φyRx¬yxA|¬φ
29 26 27 28 sylc yAyRxyxA|¬φ¬yRx¬yxA|¬φ
30 simp1 yAyRxyxA|¬φ¬yRxyA
31 nfcv _xA
32 31 elrabsf yxA|¬φyA[˙y/x]˙¬φ
33 vex yV
34 sbcng yV[˙y/x]˙¬φ¬[˙y/x]˙φ
35 33 34 ax-mp [˙y/x]˙¬φ¬[˙y/x]˙φ
36 35 anbi2i yA[˙y/x]˙¬φyA¬[˙y/x]˙φ
37 32 36 bitri yxA|¬φyA¬[˙y/x]˙φ
38 37 notbii ¬yxA|¬φ¬yA¬[˙y/x]˙φ
39 imnan yA¬¬[˙y/x]˙φ¬yA¬[˙y/x]˙φ
40 38 39 sylbb2 ¬yxA|¬φyA¬¬[˙y/x]˙φ
41 40 imp ¬yxA|¬φyA¬¬[˙y/x]˙φ
42 41 notnotrd ¬yxA|¬φyA[˙y/x]˙φ
43 29 30 42 syl2anc yAyRxyxA|¬φ¬yRx[˙y/x]˙φ
44 43 3expa yAyRxyxA|¬φ¬yRx[˙y/x]˙φ
45 44 expcom yxA|¬φ¬yRxyAyRx[˙y/x]˙φ
46 45 expd yxA|¬φ¬yRxyAyRx[˙y/x]˙φ
47 21 46 ralrimi yxA|¬φ¬yRxyAyRx[˙y/x]˙φ
48 47 1 sylibr yxA|¬φ¬yRxψ
49 48 3ad2ant3 RFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRxψ
50 simp12 RFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRxxAψφ
51 simp3 xAψxAψφxAψφ
52 51 bnj1211 xAψxAψφxxAψφ
53 simp1 xAψxAψφxA
54 simp2 xAψxAψφψ
55 sp xxAψφxAψφ
56 52 53 54 55 syl3c xAψxAψφφ
57 20 49 50 56 syl3anc RFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRxφ
58 rabid xxA|¬φxA¬φ
59 58 simprbi xxA|¬φ¬φ
60 59 3ad2ant2 RFrSeAxAψφxA¬φxxA|¬φyxA|¬φ¬yRx¬φ
61 18 57 60 bnj1304 ¬RFrSeAxAψφxA¬φ
62 61 bnj1224 RFrSeAxAψφ¬xA¬φ
63 dfral2 xAφ¬xA¬φ
64 62 63 sylibr RFrSeAxAψφxAφ