Metamath Proof Explorer


Theorem hash3tpde

Description: A set of size three is an unordered triple of three different elements. (Contributed by AV, 21-Jul-2025)

Ref Expression
Assertion hash3tpde V W V = 3 a b c a b a c b c V = a b c

Proof

Step Hyp Ref Expression
1 hash3tr V W V = 3 a b c V = a b c
2 ax-1 a b a c b c V W V = 3 V = a b c a b a c b c
3 3ianor ¬ a b a c b c ¬ a b ¬ a c ¬ b c
4 nne ¬ a b a = b
5 nne ¬ a c a = c
6 nne ¬ b c b = c
7 4 5 6 3orbi123i ¬ a b ¬ a c ¬ b c a = b a = c b = c
8 3 7 bitri ¬ a b a c b c a = b a = c b = c
9 tpeq1 a = b a b c = b b c
10 tpidm12 b b c = b c
11 9 10 eqtrdi a = b a b c = b c
12 11 eqeq2d a = b V = a b c V = b c
13 fveqeq2 V = b c V = 3 b c = 3
14 hashprlei b c Fin b c 2
15 breq1 b c = 3 b c 2 3 2
16 2lt3 2 < 3
17 2re 2
18 3re 3
19 17 18 ltnlei 2 < 3 ¬ 3 2
20 16 19 mpbi ¬ 3 2
21 20 pm2.21i 3 2 a b a c b c
22 15 21 biimtrdi b c = 3 b c 2 a b a c b c
23 22 com12 b c 2 b c = 3 a b a c b c
24 23 adantl b c Fin b c 2 b c = 3 a b a c b c
25 14 24 ax-mp b c = 3 a b a c b c
26 13 25 biimtrdi V = b c V = 3 a b a c b c
27 26 adantld V = b c V W V = 3 a b a c b c
28 12 27 biimtrdi a = b V = a b c V W V = 3 a b a c b c
29 tpeq1 a = c a b c = c b c
30 tpidm13 c b c = c b
31 29 30 eqtrdi a = c a b c = c b
32 31 eqeq2d a = c V = a b c V = c b
33 fveqeq2 V = c b V = 3 c b = 3
34 hashprlei c b Fin c b 2
35 breq1 c b = 3 c b 2 3 2
36 35 21 biimtrdi c b = 3 c b 2 a b a c b c
37 36 com12 c b 2 c b = 3 a b a c b c
38 37 adantl c b Fin c b 2 c b = 3 a b a c b c
39 34 38 ax-mp c b = 3 a b a c b c
40 33 39 biimtrdi V = c b V = 3 a b a c b c
41 40 adantld V = c b V W V = 3 a b a c b c
42 32 41 biimtrdi a = c V = a b c V W V = 3 a b a c b c
43 tpeq2 b = c a b c = a c c
44 tpidm23 a c c = a c
45 43 44 eqtrdi b = c a b c = a c
46 45 eqeq2d b = c V = a b c V = a c
47 fveqeq2 V = a c V = 3 a c = 3
48 hashprlei a c Fin a c 2
49 breq1 a c = 3 a c 2 3 2
50 49 21 biimtrdi a c = 3 a c 2 a b a c b c
51 50 com12 a c 2 a c = 3 a b a c b c
52 51 adantl a c Fin a c 2 a c = 3 a b a c b c
53 48 52 ax-mp a c = 3 a b a c b c
54 47 53 biimtrdi V = a c V = 3 a b a c b c
55 54 adantld V = a c V W V = 3 a b a c b c
56 46 55 biimtrdi b = c V = a b c V W V = 3 a b a c b c
57 28 42 56 3jaoi a = b a = c b = c V = a b c V W V = 3 a b a c b c
58 57 impcomd a = b a = c b = c V W V = 3 V = a b c a b a c b c
59 8 58 sylbi ¬ a b a c b c V W V = 3 V = a b c a b a c b c
60 2 59 pm2.61i V W V = 3 V = a b c a b a c b c
61 simpr V W V = 3 V = a b c V = a b c
62 60 61 jca V W V = 3 V = a b c a b a c b c V = a b c
63 62 ex V W V = 3 V = a b c a b a c b c V = a b c
64 63 eximdv V W V = 3 c V = a b c c a b a c b c V = a b c
65 64 2eximdv V W V = 3 a b c V = a b c a b c a b a c b c V = a b c
66 1 65 mpd V W V = 3 a b c a b a c b c V = a b c