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Mirrors > Home > MPE Home > Th. List > hash2prde | Structured version Visualization version GIF version |
Description: A set of size two is an unordered pair of two different elements. (Contributed by Alexander van der Vekens, 8-Dec-2017.) |
Ref | Expression |
---|---|
hash2prde | ⊢ ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → ∃𝑎∃𝑏(𝑎 ≠ 𝑏 ∧ 𝑉 = {𝑎, 𝑏})) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | hash2pr 13108 | . 2 ⊢ ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → ∃𝑎∃𝑏 𝑉 = {𝑎, 𝑏}) | |
2 | equid 1926 | . . . . . . 7 ⊢ 𝑏 = 𝑏 | |
3 | vex 3176 | . . . . . . . . 9 ⊢ 𝑎 ∈ V | |
4 | vex 3176 | . . . . . . . . 9 ⊢ 𝑏 ∈ V | |
5 | 3, 4, 4 | preqsn 4331 | . . . . . . . 8 ⊢ ({𝑎, 𝑏} = {𝑏} ↔ (𝑎 = 𝑏 ∧ 𝑏 = 𝑏)) |
6 | eqeq2 2621 | . . . . . . . . . . . 12 ⊢ ({𝑎, 𝑏} = {𝑏} → (𝑉 = {𝑎, 𝑏} ↔ 𝑉 = {𝑏})) | |
7 | fveq2 6103 | . . . . . . . . . . . . . 14 ⊢ (𝑉 = {𝑏} → (#‘𝑉) = (#‘{𝑏})) | |
8 | hashsng 13020 | . . . . . . . . . . . . . . 15 ⊢ (𝑏 ∈ V → (#‘{𝑏}) = 1) | |
9 | 4, 8 | ax-mp 5 | . . . . . . . . . . . . . 14 ⊢ (#‘{𝑏}) = 1 |
10 | 7, 9 | syl6eq 2660 | . . . . . . . . . . . . 13 ⊢ (𝑉 = {𝑏} → (#‘𝑉) = 1) |
11 | eqeq1 2614 | . . . . . . . . . . . . . . 15 ⊢ ((#‘𝑉) = 2 → ((#‘𝑉) = 1 ↔ 2 = 1)) | |
12 | 1ne2 11117 | . . . . . . . . . . . . . . . . 17 ⊢ 1 ≠ 2 | |
13 | df-ne 2782 | . . . . . . . . . . . . . . . . . 18 ⊢ (1 ≠ 2 ↔ ¬ 1 = 2) | |
14 | pm2.21 119 | . . . . . . . . . . . . . . . . . 18 ⊢ (¬ 1 = 2 → (1 = 2 → 𝑎 ≠ 𝑏)) | |
15 | 13, 14 | sylbi 206 | . . . . . . . . . . . . . . . . 17 ⊢ (1 ≠ 2 → (1 = 2 → 𝑎 ≠ 𝑏)) |
16 | 12, 15 | ax-mp 5 | . . . . . . . . . . . . . . . 16 ⊢ (1 = 2 → 𝑎 ≠ 𝑏) |
17 | 16 | eqcoms 2618 | . . . . . . . . . . . . . . 15 ⊢ (2 = 1 → 𝑎 ≠ 𝑏) |
18 | 11, 17 | syl6bi 242 | . . . . . . . . . . . . . 14 ⊢ ((#‘𝑉) = 2 → ((#‘𝑉) = 1 → 𝑎 ≠ 𝑏)) |
19 | 18 | adantl 481 | . . . . . . . . . . . . 13 ⊢ ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → ((#‘𝑉) = 1 → 𝑎 ≠ 𝑏)) |
20 | 10, 19 | syl5com 31 | . . . . . . . . . . . 12 ⊢ (𝑉 = {𝑏} → ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → 𝑎 ≠ 𝑏)) |
21 | 6, 20 | syl6bi 242 | . . . . . . . . . . 11 ⊢ ({𝑎, 𝑏} = {𝑏} → (𝑉 = {𝑎, 𝑏} → ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → 𝑎 ≠ 𝑏))) |
22 | 21 | com13 86 | . . . . . . . . . 10 ⊢ ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → (𝑉 = {𝑎, 𝑏} → ({𝑎, 𝑏} = {𝑏} → 𝑎 ≠ 𝑏))) |
23 | 22 | imp 444 | . . . . . . . . 9 ⊢ (((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) ∧ 𝑉 = {𝑎, 𝑏}) → ({𝑎, 𝑏} = {𝑏} → 𝑎 ≠ 𝑏)) |
24 | 23 | com12 32 | . . . . . . . 8 ⊢ ({𝑎, 𝑏} = {𝑏} → (((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) ∧ 𝑉 = {𝑎, 𝑏}) → 𝑎 ≠ 𝑏)) |
25 | 5, 24 | sylbir 224 | . . . . . . 7 ⊢ ((𝑎 = 𝑏 ∧ 𝑏 = 𝑏) → (((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) ∧ 𝑉 = {𝑎, 𝑏}) → 𝑎 ≠ 𝑏)) |
26 | 2, 25 | mpan2 703 | . . . . . 6 ⊢ (𝑎 = 𝑏 → (((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) ∧ 𝑉 = {𝑎, 𝑏}) → 𝑎 ≠ 𝑏)) |
27 | ax-1 6 | . . . . . 6 ⊢ (𝑎 ≠ 𝑏 → (((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) ∧ 𝑉 = {𝑎, 𝑏}) → 𝑎 ≠ 𝑏)) | |
28 | 26, 27 | pm2.61ine 2865 | . . . . 5 ⊢ (((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) ∧ 𝑉 = {𝑎, 𝑏}) → 𝑎 ≠ 𝑏) |
29 | simpr 476 | . . . . 5 ⊢ (((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) ∧ 𝑉 = {𝑎, 𝑏}) → 𝑉 = {𝑎, 𝑏}) | |
30 | 28, 29 | jca 553 | . . . 4 ⊢ (((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) ∧ 𝑉 = {𝑎, 𝑏}) → (𝑎 ≠ 𝑏 ∧ 𝑉 = {𝑎, 𝑏})) |
31 | 30 | ex 449 | . . 3 ⊢ ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → (𝑉 = {𝑎, 𝑏} → (𝑎 ≠ 𝑏 ∧ 𝑉 = {𝑎, 𝑏}))) |
32 | 31 | 2eximdv 1835 | . 2 ⊢ ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → (∃𝑎∃𝑏 𝑉 = {𝑎, 𝑏} → ∃𝑎∃𝑏(𝑎 ≠ 𝑏 ∧ 𝑉 = {𝑎, 𝑏}))) |
33 | 1, 32 | mpd 15 | 1 ⊢ ((𝑉 ∈ 𝑊 ∧ (#‘𝑉) = 2) → ∃𝑎∃𝑏(𝑎 ≠ 𝑏 ∧ 𝑉 = {𝑎, 𝑏})) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 383 = wceq 1475 ∃wex 1695 ∈ wcel 1977 ≠ wne 2780 Vcvv 3173 {csn 4125 {cpr 4127 ‘cfv 5804 1c1 9816 2c2 10947 #chash 12979 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-8 1979 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-rep 4699 ax-sep 4709 ax-nul 4717 ax-pow 4769 ax-pr 4833 ax-un 6847 ax-cnex 9871 ax-resscn 9872 ax-1cn 9873 ax-icn 9874 ax-addcl 9875 ax-addrcl 9876 ax-mulcl 9877 ax-mulrcl 9878 ax-mulcom 9879 ax-addass 9880 ax-mulass 9881 ax-distr 9882 ax-i2m1 9883 ax-1ne0 9884 ax-1rid 9885 ax-rnegex 9886 ax-rrecex 9887 ax-cnre 9888 ax-pre-lttri 9889 ax-pre-lttrn 9890 ax-pre-ltadd 9891 ax-pre-mulgt0 9892 |
This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3or 1032 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-eu 2462 df-mo 2463 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ne 2782 df-nel 2783 df-ral 2901 df-rex 2902 df-reu 2903 df-rmo 2904 df-rab 2905 df-v 3175 df-sbc 3403 df-csb 3500 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-pss 3556 df-nul 3875 df-if 4037 df-pw 4110 df-sn 4126 df-pr 4128 df-tp 4130 df-op 4132 df-uni 4373 df-int 4411 df-iun 4457 df-br 4584 df-opab 4644 df-mpt 4645 df-tr 4681 df-eprel 4949 df-id 4953 df-po 4959 df-so 4960 df-fr 4997 df-we 4999 df-xp 5044 df-rel 5045 df-cnv 5046 df-co 5047 df-dm 5048 df-rn 5049 df-res 5050 df-ima 5051 df-pred 5597 df-ord 5643 df-on 5644 df-lim 5645 df-suc 5646 df-iota 5768 df-fun 5806 df-fn 5807 df-f 5808 df-f1 5809 df-fo 5810 df-f1o 5811 df-fv 5812 df-riota 6511 df-ov 6552 df-oprab 6553 df-mpt2 6554 df-om 6958 df-1st 7059 df-2nd 7060 df-wrecs 7294 df-recs 7355 df-rdg 7393 df-1o 7447 df-2o 7448 df-oadd 7451 df-er 7629 df-en 7842 df-dom 7843 df-sdom 7844 df-fin 7845 df-card 8648 df-cda 8873 df-pnf 9955 df-mnf 9956 df-xr 9957 df-ltxr 9958 df-le 9959 df-sub 10147 df-neg 10148 df-nn 10898 df-2 10956 df-n0 11170 df-z 11255 df-uz 11564 df-fz 12198 df-hash 12980 |
This theorem is referenced by: hash2exprb 13110 umgredg 25812 usgrarnedg 25913 cusgrarn 25988 frgraregord013 26645 av-frgraregord013 41549 |
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