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Theorem hashbc 13432
Description: The binomial coefficient counts the number of subsets of a finite set of a given size. This is Metamath 100 proof #58 (formula for the number of combinations). (Contributed by Mario Carneiro, 13-Jul-2014.)
Assertion
Ref Expression
hashbc ((𝐴 ∈ Fin ∧ 𝐾 ∈ ℤ) → ((♯‘𝐴)C𝐾) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝐾}))
Distinct variable groups:   𝑥,𝐴   𝑥,𝐾

Proof of Theorem hashbc
Dummy variables 𝑗 𝑘 𝑤 𝑦 𝑧 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 fveq2 6330 . . . . . 6 (𝑤 = ∅ → (♯‘𝑤) = (♯‘∅))
21oveq1d 6806 . . . . 5 (𝑤 = ∅ → ((♯‘𝑤)C𝑘) = ((♯‘∅)C𝑘))
3 pweq 4300 . . . . . . 7 (𝑤 = ∅ → 𝒫 𝑤 = 𝒫 ∅)
4 rabeq 3342 . . . . . . 7 (𝒫 𝑤 = 𝒫 ∅ → {𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘})
53, 4syl 17 . . . . . 6 (𝑤 = ∅ → {𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘})
65fveq2d 6334 . . . . 5 (𝑤 = ∅ → (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}))
72, 6eqeq12d 2786 . . . 4 (𝑤 = ∅ → (((♯‘𝑤)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) ↔ ((♯‘∅)C𝑘) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘})))
87ralbidv 3135 . . 3 (𝑤 = ∅ → (∀𝑘 ∈ ℤ ((♯‘𝑤)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) ↔ ∀𝑘 ∈ ℤ ((♯‘∅)C𝑘) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘})))
9 fveq2 6330 . . . . . 6 (𝑤 = 𝑦 → (♯‘𝑤) = (♯‘𝑦))
109oveq1d 6806 . . . . 5 (𝑤 = 𝑦 → ((♯‘𝑤)C𝑘) = ((♯‘𝑦)C𝑘))
11 pweq 4300 . . . . . . 7 (𝑤 = 𝑦 → 𝒫 𝑤 = 𝒫 𝑦)
12 rabeq 3342 . . . . . . 7 (𝒫 𝑤 = 𝒫 𝑦 → {𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘})
1311, 12syl 17 . . . . . 6 (𝑤 = 𝑦 → {𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘})
1413fveq2d 6334 . . . . 5 (𝑤 = 𝑦 → (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘}))
1510, 14eqeq12d 2786 . . . 4 (𝑤 = 𝑦 → (((♯‘𝑤)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) ↔ ((♯‘𝑦)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘})))
1615ralbidv 3135 . . 3 (𝑤 = 𝑦 → (∀𝑘 ∈ ℤ ((♯‘𝑤)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) ↔ ∀𝑘 ∈ ℤ ((♯‘𝑦)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘})))
17 fveq2 6330 . . . . . 6 (𝑤 = (𝑦 ∪ {𝑧}) → (♯‘𝑤) = (♯‘(𝑦 ∪ {𝑧})))
1817oveq1d 6806 . . . . 5 (𝑤 = (𝑦 ∪ {𝑧}) → ((♯‘𝑤)C𝑘) = ((♯‘(𝑦 ∪ {𝑧}))C𝑘))
19 pweq 4300 . . . . . . 7 (𝑤 = (𝑦 ∪ {𝑧}) → 𝒫 𝑤 = 𝒫 (𝑦 ∪ {𝑧}))
20 rabeq 3342 . . . . . . 7 (𝒫 𝑤 = 𝒫 (𝑦 ∪ {𝑧}) → {𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘})
2119, 20syl 17 . . . . . 6 (𝑤 = (𝑦 ∪ {𝑧}) → {𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘})
2221fveq2d 6334 . . . . 5 (𝑤 = (𝑦 ∪ {𝑧}) → (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) = (♯‘{𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘}))
2318, 22eqeq12d 2786 . . . 4 (𝑤 = (𝑦 ∪ {𝑧}) → (((♯‘𝑤)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) ↔ ((♯‘(𝑦 ∪ {𝑧}))C𝑘) = (♯‘{𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘})))
2423ralbidv 3135 . . 3 (𝑤 = (𝑦 ∪ {𝑧}) → (∀𝑘 ∈ ℤ ((♯‘𝑤)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) ↔ ∀𝑘 ∈ ℤ ((♯‘(𝑦 ∪ {𝑧}))C𝑘) = (♯‘{𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘})))
25 fveq2 6330 . . . . . 6 (𝑤 = 𝐴 → (♯‘𝑤) = (♯‘𝐴))
2625oveq1d 6806 . . . . 5 (𝑤 = 𝐴 → ((♯‘𝑤)C𝑘) = ((♯‘𝐴)C𝑘))
27 pweq 4300 . . . . . . 7 (𝑤 = 𝐴 → 𝒫 𝑤 = 𝒫 𝐴)
28 rabeq 3342 . . . . . . 7 (𝒫 𝑤 = 𝒫 𝐴 → {𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘})
2927, 28syl 17 . . . . . 6 (𝑤 = 𝐴 → {𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘})
3029fveq2d 6334 . . . . 5 (𝑤 = 𝐴 → (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘}))
3126, 30eqeq12d 2786 . . . 4 (𝑤 = 𝐴 → (((♯‘𝑤)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) ↔ ((♯‘𝐴)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘})))
3231ralbidv 3135 . . 3 (𝑤 = 𝐴 → (∀𝑘 ∈ ℤ ((♯‘𝑤)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑤 ∣ (♯‘𝑥) = 𝑘}) ↔ ∀𝑘 ∈ ℤ ((♯‘𝐴)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘})))
33 hash0 13353 . . . . . . . . . 10 (♯‘∅) = 0
3433a1i 11 . . . . . . . . 9 (𝑘 ∈ (0...0) → (♯‘∅) = 0)
35 elfz1eq 12552 . . . . . . . . 9 (𝑘 ∈ (0...0) → 𝑘 = 0)
3634, 35oveq12d 6809 . . . . . . . 8 (𝑘 ∈ (0...0) → ((♯‘∅)C𝑘) = (0C0))
37 0nn0 11507 . . . . . . . . 9 0 ∈ ℕ0
38 bcn0 13294 . . . . . . . . 9 (0 ∈ ℕ0 → (0C0) = 1)
3937, 38ax-mp 5 . . . . . . . 8 (0C0) = 1
4036, 39syl6eq 2821 . . . . . . 7 (𝑘 ∈ (0...0) → ((♯‘∅)C𝑘) = 1)
41 pw0 4478 . . . . . . . . . 10 𝒫 ∅ = {∅}
4235eqcomd 2777 . . . . . . . . . . . 12 (𝑘 ∈ (0...0) → 0 = 𝑘)
4341raleqi 3291 . . . . . . . . . . . . 13 (∀𝑥 ∈ 𝒫 ∅(♯‘𝑥) = 𝑘 ↔ ∀𝑥 ∈ {∅} (♯‘𝑥) = 𝑘)
44 0ex 4924 . . . . . . . . . . . . . 14 ∅ ∈ V
45 fveq2 6330 . . . . . . . . . . . . . . . 16 (𝑥 = ∅ → (♯‘𝑥) = (♯‘∅))
4645, 33syl6eq 2821 . . . . . . . . . . . . . . 15 (𝑥 = ∅ → (♯‘𝑥) = 0)
4746eqeq1d 2773 . . . . . . . . . . . . . 14 (𝑥 = ∅ → ((♯‘𝑥) = 𝑘 ↔ 0 = 𝑘))
4844, 47ralsn 4360 . . . . . . . . . . . . 13 (∀𝑥 ∈ {∅} (♯‘𝑥) = 𝑘 ↔ 0 = 𝑘)
4943, 48bitri 264 . . . . . . . . . . . 12 (∀𝑥 ∈ 𝒫 ∅(♯‘𝑥) = 𝑘 ↔ 0 = 𝑘)
5042, 49sylibr 224 . . . . . . . . . . 11 (𝑘 ∈ (0...0) → ∀𝑥 ∈ 𝒫 ∅(♯‘𝑥) = 𝑘)
51 rabid2 3267 . . . . . . . . . . 11 (𝒫 ∅ = {𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘} ↔ ∀𝑥 ∈ 𝒫 ∅(♯‘𝑥) = 𝑘)
5250, 51sylibr 224 . . . . . . . . . 10 (𝑘 ∈ (0...0) → 𝒫 ∅ = {𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘})
5341, 52syl5reqr 2820 . . . . . . . . 9 (𝑘 ∈ (0...0) → {𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘} = {∅})
5453fveq2d 6334 . . . . . . . 8 (𝑘 ∈ (0...0) → (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}) = (♯‘{∅}))
55 hashsng 13354 . . . . . . . . 9 (∅ ∈ V → (♯‘{∅}) = 1)
5644, 55ax-mp 5 . . . . . . . 8 (♯‘{∅}) = 1
5754, 56syl6eq 2821 . . . . . . 7 (𝑘 ∈ (0...0) → (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}) = 1)
5840, 57eqtr4d 2808 . . . . . 6 (𝑘 ∈ (0...0) → ((♯‘∅)C𝑘) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}))
5958adantl 467 . . . . 5 ((𝑘 ∈ ℤ ∧ 𝑘 ∈ (0...0)) → ((♯‘∅)C𝑘) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}))
6033oveq1i 6801 . . . . . 6 ((♯‘∅)C𝑘) = (0C𝑘)
61 bcval3 13290 . . . . . . . 8 ((0 ∈ ℕ0𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → (0C𝑘) = 0)
6237, 61mp3an1 1559 . . . . . . 7 ((𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → (0C𝑘) = 0)
63 id 22 . . . . . . . . . . . . . 14 (0 = 𝑘 → 0 = 𝑘)
64 0z 11588 . . . . . . . . . . . . . . 15 0 ∈ ℤ
65 elfz3 12551 . . . . . . . . . . . . . . 15 (0 ∈ ℤ → 0 ∈ (0...0))
6664, 65ax-mp 5 . . . . . . . . . . . . . 14 0 ∈ (0...0)
6763, 66syl6eqelr 2859 . . . . . . . . . . . . 13 (0 = 𝑘𝑘 ∈ (0...0))
6867con3i 151 . . . . . . . . . . . 12 𝑘 ∈ (0...0) → ¬ 0 = 𝑘)
6968adantl 467 . . . . . . . . . . 11 ((𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → ¬ 0 = 𝑘)
7041raleqi 3291 . . . . . . . . . . . 12 (∀𝑥 ∈ 𝒫 ∅ ¬ (♯‘𝑥) = 𝑘 ↔ ∀𝑥 ∈ {∅} ¬ (♯‘𝑥) = 𝑘)
7147notbid 307 . . . . . . . . . . . . 13 (𝑥 = ∅ → (¬ (♯‘𝑥) = 𝑘 ↔ ¬ 0 = 𝑘))
7244, 71ralsn 4360 . . . . . . . . . . . 12 (∀𝑥 ∈ {∅} ¬ (♯‘𝑥) = 𝑘 ↔ ¬ 0 = 𝑘)
7370, 72bitri 264 . . . . . . . . . . 11 (∀𝑥 ∈ 𝒫 ∅ ¬ (♯‘𝑥) = 𝑘 ↔ ¬ 0 = 𝑘)
7469, 73sylibr 224 . . . . . . . . . 10 ((𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → ∀𝑥 ∈ 𝒫 ∅ ¬ (♯‘𝑥) = 𝑘)
75 rabeq0 4103 . . . . . . . . . 10 ({𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘} = ∅ ↔ ∀𝑥 ∈ 𝒫 ∅ ¬ (♯‘𝑥) = 𝑘)
7674, 75sylibr 224 . . . . . . . . 9 ((𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → {𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘} = ∅)
7776fveq2d 6334 . . . . . . . 8 ((𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}) = (♯‘∅))
7877, 33syl6eq 2821 . . . . . . 7 ((𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}) = 0)
7962, 78eqtr4d 2808 . . . . . 6 ((𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → (0C𝑘) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}))
8060, 79syl5eq 2817 . . . . 5 ((𝑘 ∈ ℤ ∧ ¬ 𝑘 ∈ (0...0)) → ((♯‘∅)C𝑘) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}))
8159, 80pm2.61dan 814 . . . 4 (𝑘 ∈ ℤ → ((♯‘∅)C𝑘) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘}))
8281rgen 3071 . . 3 𝑘 ∈ ℤ ((♯‘∅)C𝑘) = (♯‘{𝑥 ∈ 𝒫 ∅ ∣ (♯‘𝑥) = 𝑘})
83 oveq2 6799 . . . . . 6 (𝑘 = 𝑗 → ((♯‘𝑦)C𝑘) = ((♯‘𝑦)C𝑗))
84 eqeq2 2782 . . . . . . . . 9 (𝑘 = 𝑗 → ((♯‘𝑥) = 𝑘 ↔ (♯‘𝑥) = 𝑗))
8584rabbidv 3339 . . . . . . . 8 (𝑘 = 𝑗 → {𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑗})
86 fveq2 6330 . . . . . . . . . 10 (𝑥 = 𝑧 → (♯‘𝑥) = (♯‘𝑧))
8786eqeq1d 2773 . . . . . . . . 9 (𝑥 = 𝑧 → ((♯‘𝑥) = 𝑗 ↔ (♯‘𝑧) = 𝑗))
8887cbvrabv 3349 . . . . . . . 8 {𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑗} = {𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}
8985, 88syl6eq 2821 . . . . . . 7 (𝑘 = 𝑗 → {𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘} = {𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗})
9089fveq2d 6334 . . . . . 6 (𝑘 = 𝑗 → (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘}) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))
9183, 90eqeq12d 2786 . . . . 5 (𝑘 = 𝑗 → (((♯‘𝑦)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘}) ↔ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗})))
9291cbvralv 3320 . . . 4 (∀𝑘 ∈ ℤ ((♯‘𝑦)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘}) ↔ ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))
93 simpll 750 . . . . . . 7 (((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) ∧ (𝑘 ∈ ℤ ∧ ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))) → 𝑦 ∈ Fin)
94 simplr 752 . . . . . . 7 (((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) ∧ (𝑘 ∈ ℤ ∧ ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))) → ¬ 𝑧𝑦)
95 simprr 756 . . . . . . . 8 (((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) ∧ (𝑘 ∈ ℤ ∧ ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))) → ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))
9688fveq2i 6333 . . . . . . . . . 10 (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑗}) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗})
9796eqeq2i 2783 . . . . . . . . 9 (((♯‘𝑦)C𝑗) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑗}) ↔ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))
9897ralbii 3129 . . . . . . . 8 (∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑗}) ↔ ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))
9995, 98sylibr 224 . . . . . . 7 (((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) ∧ (𝑘 ∈ ℤ ∧ ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))) → ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑗}))
100 simprl 754 . . . . . . 7 (((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) ∧ (𝑘 ∈ ℤ ∧ ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))) → 𝑘 ∈ ℤ)
10193, 94, 99, 100hashbclem 13431 . . . . . 6 (((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) ∧ (𝑘 ∈ ℤ ∧ ∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}))) → ((♯‘(𝑦 ∪ {𝑧}))C𝑘) = (♯‘{𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘}))
102101expr 444 . . . . 5 (((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) ∧ 𝑘 ∈ ℤ) → (∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}) → ((♯‘(𝑦 ∪ {𝑧}))C𝑘) = (♯‘{𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘})))
103102ralrimdva 3118 . . . 4 ((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) → (∀𝑗 ∈ ℤ ((♯‘𝑦)C𝑗) = (♯‘{𝑧 ∈ 𝒫 𝑦 ∣ (♯‘𝑧) = 𝑗}) → ∀𝑘 ∈ ℤ ((♯‘(𝑦 ∪ {𝑧}))C𝑘) = (♯‘{𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘})))
10492, 103syl5bi 232 . . 3 ((𝑦 ∈ Fin ∧ ¬ 𝑧𝑦) → (∀𝑘 ∈ ℤ ((♯‘𝑦)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝑦 ∣ (♯‘𝑥) = 𝑘}) → ∀𝑘 ∈ ℤ ((♯‘(𝑦 ∪ {𝑧}))C𝑘) = (♯‘{𝑥 ∈ 𝒫 (𝑦 ∪ {𝑧}) ∣ (♯‘𝑥) = 𝑘})))
1058, 16, 24, 32, 82, 104findcard2s 8355 . 2 (𝐴 ∈ Fin → ∀𝑘 ∈ ℤ ((♯‘𝐴)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘}))
106 oveq2 6799 . . . 4 (𝑘 = 𝐾 → ((♯‘𝐴)C𝑘) = ((♯‘𝐴)C𝐾))
107 eqeq2 2782 . . . . . 6 (𝑘 = 𝐾 → ((♯‘𝑥) = 𝑘 ↔ (♯‘𝑥) = 𝐾))
108107rabbidv 3339 . . . . 5 (𝑘 = 𝐾 → {𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘} = {𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝐾})
109108fveq2d 6334 . . . 4 (𝑘 = 𝐾 → (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘}) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝐾}))
110106, 109eqeq12d 2786 . . 3 (𝑘 = 𝐾 → (((♯‘𝐴)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘}) ↔ ((♯‘𝐴)C𝐾) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝐾})))
111110rspccva 3459 . 2 ((∀𝑘 ∈ ℤ ((♯‘𝐴)C𝑘) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝑘}) ∧ 𝐾 ∈ ℤ) → ((♯‘𝐴)C𝐾) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝐾}))
112105, 111sylan 569 1 ((𝐴 ∈ Fin ∧ 𝐾 ∈ ℤ) → ((♯‘𝐴)C𝐾) = (♯‘{𝑥 ∈ 𝒫 𝐴 ∣ (♯‘𝑥) = 𝐾}))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wa 382   = wceq 1631  wcel 2145  wral 3061  {crab 3065  Vcvv 3351  cun 3721  c0 4063  𝒫 cpw 4297  {csn 4316  cfv 6029  (class class class)co 6791  Fincfn 8107  0cc0 10136  1c1 10137  0cn0 11492  cz 11577  ...cfz 12526  Ccbc 13286  chash 13314
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1870  ax-4 1885  ax-5 1991  ax-6 2057  ax-7 2093  ax-8 2147  ax-9 2154  ax-10 2174  ax-11 2190  ax-12 2203  ax-13 2408  ax-ext 2751  ax-rep 4904  ax-sep 4915  ax-nul 4923  ax-pow 4974  ax-pr 5034  ax-un 7094  ax-cnex 10192  ax-resscn 10193  ax-1cn 10194  ax-icn 10195  ax-addcl 10196  ax-addrcl 10197  ax-mulcl 10198  ax-mulrcl 10199  ax-mulcom 10200  ax-addass 10201  ax-mulass 10202  ax-distr 10203  ax-i2m1 10204  ax-1ne0 10205  ax-1rid 10206  ax-rnegex 10207  ax-rrecex 10208  ax-cnre 10209  ax-pre-lttri 10210  ax-pre-lttrn 10211  ax-pre-ltadd 10212  ax-pre-mulgt0 10213
This theorem depends on definitions:  df-bi 197  df-an 383  df-or 837  df-3or 1072  df-3an 1073  df-tru 1634  df-ex 1853  df-nf 1858  df-sb 2050  df-eu 2622  df-mo 2623  df-clab 2758  df-cleq 2764  df-clel 2767  df-nfc 2902  df-ne 2944  df-nel 3047  df-ral 3066  df-rex 3067  df-reu 3068  df-rmo 3069  df-rab 3070  df-v 3353  df-sbc 3588  df-csb 3683  df-dif 3726  df-un 3728  df-in 3730  df-ss 3737  df-pss 3739  df-nul 4064  df-if 4226  df-pw 4299  df-sn 4317  df-pr 4319  df-tp 4321  df-op 4323  df-uni 4575  df-int 4612  df-iun 4656  df-br 4787  df-opab 4847  df-mpt 4864  df-tr 4887  df-id 5157  df-eprel 5162  df-po 5170  df-so 5171  df-fr 5208  df-we 5210  df-xp 5255  df-rel 5256  df-cnv 5257  df-co 5258  df-dm 5259  df-rn 5260  df-res 5261  df-ima 5262  df-pred 5821  df-ord 5867  df-on 5868  df-lim 5869  df-suc 5870  df-iota 5992  df-fun 6031  df-fn 6032  df-f 6033  df-f1 6034  df-fo 6035  df-f1o 6036  df-fv 6037  df-riota 6752  df-ov 6794  df-oprab 6795  df-mpt2 6796  df-om 7211  df-1st 7313  df-2nd 7314  df-wrecs 7557  df-recs 7619  df-rdg 7657  df-1o 7711  df-2o 7712  df-oadd 7715  df-er 7894  df-map 8009  df-en 8108  df-dom 8109  df-sdom 8110  df-fin 8111  df-card 8963  df-cda 9190  df-pnf 10276  df-mnf 10277  df-xr 10278  df-ltxr 10279  df-le 10280  df-sub 10468  df-neg 10469  df-div 10885  df-nn 11221  df-n0 11493  df-z 11578  df-uz 11887  df-rp 12029  df-fz 12527  df-seq 13002  df-fac 13258  df-bc 13287  df-hash 13315
This theorem is referenced by:  hashbc2  15910  sylow1lem1  18213  musum  25131  ballotlem1  30881  ballotlem2  30883
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