Metamath Proof Explorer


Definition df-ram

Description: Define the Ramsey number function. The input is a number m for the size of the edges of the hypergraph, and a tuple r from the finite color set to lower bounds for each color. The Ramsey number ( M Ramsey R ) is the smallest number such that for any set S with ( M Ramsey R ) <_ # S and any coloring F of the set of M -element subsets of S (with color set dom R ), there is a color c e. dom R and a subset x C_ S such that R ( c ) <_ # x and all the hyperedges of x (that is, subsets of x of size M ) have color c . (Contributed by Mario Carneiro, 20-Apr-2015) (Revised by AV, 14-Sep-2020)

Ref Expression
Assertion df-ram Ramsey = ( 𝑚 ∈ ℕ0 , 𝑟 ∈ V ↦ inf ( { 𝑛 ∈ ℕ0 ∣ ∀ 𝑠 ( 𝑛 ≤ ( ♯ ‘ 𝑠 ) → ∀ 𝑓 ∈ ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } ) ∃ 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) ) ) } , ℝ* , < ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cram Ramsey
1 vm 𝑚
2 cn0 0
3 vr 𝑟
4 cvv V
5 vn 𝑛
6 vs 𝑠
7 5 cv 𝑛
8 cle
9 chash
10 6 cv 𝑠
11 10 9 cfv ( ♯ ‘ 𝑠 )
12 7 11 8 wbr 𝑛 ≤ ( ♯ ‘ 𝑠 )
13 vf 𝑓
14 3 cv 𝑟
15 14 cdm dom 𝑟
16 cmap m
17 vy 𝑦
18 10 cpw 𝒫 𝑠
19 17 cv 𝑦
20 19 9 cfv ( ♯ ‘ 𝑦 )
21 1 cv 𝑚
22 20 21 wceq ( ♯ ‘ 𝑦 ) = 𝑚
23 22 17 18 crab { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 }
24 15 23 16 co ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } )
25 vc 𝑐
26 vx 𝑥
27 25 cv 𝑐
28 27 14 cfv ( 𝑟𝑐 )
29 26 cv 𝑥
30 29 9 cfv ( ♯ ‘ 𝑥 )
31 28 30 8 wbr ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 )
32 29 cpw 𝒫 𝑥
33 13 cv 𝑓
34 19 33 cfv ( 𝑓𝑦 )
35 34 27 wceq ( 𝑓𝑦 ) = 𝑐
36 22 35 wi ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 )
37 36 17 32 wral 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 )
38 31 37 wa ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) )
39 38 26 18 wrex 𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) )
40 39 25 15 wrex 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) )
41 40 13 24 wral 𝑓 ∈ ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } ) ∃ 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) )
42 12 41 wi ( 𝑛 ≤ ( ♯ ‘ 𝑠 ) → ∀ 𝑓 ∈ ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } ) ∃ 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) ) )
43 42 6 wal 𝑠 ( 𝑛 ≤ ( ♯ ‘ 𝑠 ) → ∀ 𝑓 ∈ ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } ) ∃ 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) ) )
44 43 5 2 crab { 𝑛 ∈ ℕ0 ∣ ∀ 𝑠 ( 𝑛 ≤ ( ♯ ‘ 𝑠 ) → ∀ 𝑓 ∈ ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } ) ∃ 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) ) ) }
45 cxr *
46 clt <
47 44 45 46 cinf inf ( { 𝑛 ∈ ℕ0 ∣ ∀ 𝑠 ( 𝑛 ≤ ( ♯ ‘ 𝑠 ) → ∀ 𝑓 ∈ ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } ) ∃ 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) ) ) } , ℝ* , < )
48 1 3 2 4 47 cmpo ( 𝑚 ∈ ℕ0 , 𝑟 ∈ V ↦ inf ( { 𝑛 ∈ ℕ0 ∣ ∀ 𝑠 ( 𝑛 ≤ ( ♯ ‘ 𝑠 ) → ∀ 𝑓 ∈ ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } ) ∃ 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) ) ) } , ℝ* , < ) )
49 0 48 wceq Ramsey = ( 𝑚 ∈ ℕ0 , 𝑟 ∈ V ↦ inf ( { 𝑛 ∈ ℕ0 ∣ ∀ 𝑠 ( 𝑛 ≤ ( ♯ ‘ 𝑠 ) → ∀ 𝑓 ∈ ( dom 𝑟m { 𝑦 ∈ 𝒫 𝑠 ∣ ( ♯ ‘ 𝑦 ) = 𝑚 } ) ∃ 𝑐 ∈ dom 𝑟𝑥 ∈ 𝒫 𝑠 ( ( 𝑟𝑐 ) ≤ ( ♯ ‘ 𝑥 ) ∧ ∀ 𝑦 ∈ 𝒫 𝑥 ( ( ♯ ‘ 𝑦 ) = 𝑚 → ( 𝑓𝑦 ) = 𝑐 ) ) ) } , ℝ* , < ) )