Theorem metf1o 38434

Description: Use a bijection with a metric space to construct a metric on a set. (Contributed by Jeff Madsen, 2-Sep-2009.)

Hypothesis

Ref	Expression
metf1o.2	⊢ 𝑁 = (𝑥 ∈ 𝑌, 𝑦 ∈ 𝑌 ↦ ((𝐹‘𝑥)𝑀(𝐹‘𝑦)))

Assertion

Ref	Expression
metf1o	⊢ ((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → 𝑁 ∈ (Met‘𝑌))

Distinct variable groups:   𝑥,𝑀,𝑦   𝑥,𝑋,𝑦   𝑥,𝑌,𝑦   𝑥,𝐹,𝑦   𝑥,𝐴,𝑦

Allowed substitution hints:   𝑁(𝑥, 𝑦)

Proof of Theorem metf1o

Dummy variables 𝑢 𝑣 𝑤 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		f1of 6820	. . . . . . 7 ⊢ (𝐹:𝑌–1-1-onto→𝑋 → 𝐹:𝑌⟶𝑋)
2		ffvelcdm 7076	. . . . . . . . 9 ⊢ ((𝐹:𝑌⟶𝑋 ∧ 𝑥 ∈ 𝑌) → (𝐹‘𝑥) ∈ 𝑋)
3	2	ex 417	. . . . . . . 8 ⊢ (𝐹:𝑌⟶𝑋 → (𝑥 ∈ 𝑌 → (𝐹‘𝑥) ∈ 𝑋))
4		ffvelcdm 7076	. . . . . . . . 9 ⊢ ((𝐹:𝑌⟶𝑋 ∧ 𝑦 ∈ 𝑌) → (𝐹‘𝑦) ∈ 𝑋)
5	4	ex 417	. . . . . . . 8 ⊢ (𝐹:𝑌⟶𝑋 → (𝑦 ∈ 𝑌 → (𝐹‘𝑦) ∈ 𝑋))
6	3, 5	anim12d 620	. . . . . . 7 ⊢ (𝐹:𝑌⟶𝑋 → ((𝑥 ∈ 𝑌 ∧ 𝑦 ∈ 𝑌) → ((𝐹‘𝑥) ∈ 𝑋 ∧ (𝐹‘𝑦) ∈ 𝑋)))
7	1, 6	syl 18	. . . . . 6 ⊢ (𝐹:𝑌–1-1-onto→𝑋 → ((𝑥 ∈ 𝑌 ∧ 𝑦 ∈ 𝑌) → ((𝐹‘𝑥) ∈ 𝑋 ∧ (𝐹‘𝑦) ∈ 𝑋)))
8		metcl 24498	. . . . . . 7 ⊢ ((𝑀 ∈ (Met‘𝑋) ∧ (𝐹‘𝑥) ∈ 𝑋 ∧ (𝐹‘𝑦) ∈ 𝑋) → ((𝐹‘𝑥)𝑀(𝐹‘𝑦)) ∈ ℝ)
9	8	3expib 1140	. . . . . 6 ⊢ (𝑀 ∈ (Met‘𝑋) → (((𝐹‘𝑥) ∈ 𝑋 ∧ (𝐹‘𝑦) ∈ 𝑋) → ((𝐹‘𝑥)𝑀(𝐹‘𝑦)) ∈ ℝ))
10	7, 9	sylan9r 517	. . . . 5 ⊢ ((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → ((𝑥 ∈ 𝑌 ∧ 𝑦 ∈ 𝑌) → ((𝐹‘𝑥)𝑀(𝐹‘𝑦)) ∈ ℝ))
11	10	3adant1 1148	. . . 4 ⊢ ((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → ((𝑥 ∈ 𝑌 ∧ 𝑦 ∈ 𝑌) → ((𝐹‘𝑥)𝑀(𝐹‘𝑦)) ∈ ℝ))
12	11	ralrimivv 3206	. . 3 ⊢ ((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → ∀𝑥 ∈ 𝑌 ∀𝑦 ∈ 𝑌 ((𝐹‘𝑥)𝑀(𝐹‘𝑦)) ∈ ℝ)
13		metf1o.2	. . . 4 ⊢ 𝑁 = (𝑥 ∈ 𝑌, 𝑦 ∈ 𝑌 ↦ ((𝐹‘𝑥)𝑀(𝐹‘𝑦)))
14	13	fmpo 8061	. . 3 ⊢ (∀𝑥 ∈ 𝑌 ∀𝑦 ∈ 𝑌 ((𝐹‘𝑥)𝑀(𝐹‘𝑦)) ∈ ℝ ↔ 𝑁:(𝑌 × 𝑌)⟶ℝ)
15	12, 14	sylib 221	. 2 ⊢ ((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → 𝑁:(𝑌 × 𝑌)⟶ℝ)
16		fveq2 6881	. . . . . . . . . . 11 ⊢ (𝑥 = 𝑢 → (𝐹‘𝑥) = (𝐹‘𝑢))
17	16	oveq1d 7425	. . . . . . . . . 10 ⊢ (𝑥 = 𝑢 → ((𝐹‘𝑥)𝑀(𝐹‘𝑦)) = ((𝐹‘𝑢)𝑀(𝐹‘𝑦)))
18		fveq2 6881	. . . . . . . . . . 11 ⊢ (𝑦 = 𝑣 → (𝐹‘𝑦) = (𝐹‘𝑣))
19	18	oveq2d 7426	. . . . . . . . . 10 ⊢ (𝑦 = 𝑣 → ((𝐹‘𝑢)𝑀(𝐹‘𝑦)) = ((𝐹‘𝑢)𝑀(𝐹‘𝑣)))
20		ovex 7443	. . . . . . . . . 10 ⊢ ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ∈ V
21	17, 19, 13, 20	ovmpo 7570	. . . . . . . . 9 ⊢ ((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) → (𝑢𝑁𝑣) = ((𝐹‘𝑢)𝑀(𝐹‘𝑣)))
22	21	eqeq1d 2765	. . . . . . . 8 ⊢ ((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) → ((𝑢𝑁𝑣) = 0 ↔ ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) = 0))
23	22	adantl 486	. . . . . . 7 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → ((𝑢𝑁𝑣) = 0 ↔ ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) = 0))
24		ffvelcdm 7076	. . . . . . . . . . . . 13 ⊢ ((𝐹:𝑌⟶𝑋 ∧ 𝑢 ∈ 𝑌) → (𝐹‘𝑢) ∈ 𝑋)
25	24	ex 417	. . . . . . . . . . . 12 ⊢ (𝐹:𝑌⟶𝑋 → (𝑢 ∈ 𝑌 → (𝐹‘𝑢) ∈ 𝑋))
26		ffvelcdm 7076	. . . . . . . . . . . . 13 ⊢ ((𝐹:𝑌⟶𝑋 ∧ 𝑣 ∈ 𝑌) → (𝐹‘𝑣) ∈ 𝑋)
27	26	ex 417	. . . . . . . . . . . 12 ⊢ (𝐹:𝑌⟶𝑋 → (𝑣 ∈ 𝑌 → (𝐹‘𝑣) ∈ 𝑋))
28	25, 27	anim12d 620	. . . . . . . . . . 11 ⊢ (𝐹:𝑌⟶𝑋 → ((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) → ((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋)))
29	1, 28	syl 18	. . . . . . . . . 10 ⊢ (𝐹:𝑌–1-1-onto→𝑋 → ((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) → ((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋)))
30	29	imp 411	. . . . . . . . 9 ⊢ ((𝐹:𝑌–1-1-onto→𝑋 ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → ((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋))
31	30	adantll 726	. . . . . . . 8 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → ((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋))
32		meteq0 24505	. . . . . . . . . 10 ⊢ ((𝑀 ∈ (Met‘𝑋) ∧ (𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) → (((𝐹‘𝑢)𝑀(𝐹‘𝑣)) = 0 ↔ (𝐹‘𝑢) = (𝐹‘𝑣)))
33	32	3expb 1138	. . . . . . . . 9 ⊢ ((𝑀 ∈ (Met‘𝑋) ∧ ((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋)) → (((𝐹‘𝑢)𝑀(𝐹‘𝑣)) = 0 ↔ (𝐹‘𝑢) = (𝐹‘𝑣)))
34	33	adantlr 727	. . . . . . . 8 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ ((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋)) → (((𝐹‘𝑢)𝑀(𝐹‘𝑣)) = 0 ↔ (𝐹‘𝑢) = (𝐹‘𝑣)))
35	31, 34	syldan 602	. . . . . . 7 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → (((𝐹‘𝑢)𝑀(𝐹‘𝑣)) = 0 ↔ (𝐹‘𝑢) = (𝐹‘𝑣)))
36		f1of1 6819	. . . . . . . . 9 ⊢ (𝐹:𝑌–1-1-onto→𝑋 → 𝐹:𝑌–1-1→𝑋)
37		f1fveq 7260	. . . . . . . . 9 ⊢ ((𝐹:𝑌–1-1→𝑋 ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → ((𝐹‘𝑢) = (𝐹‘𝑣) ↔ 𝑢 = 𝑣))
38	36, 37	sylan 591	. . . . . . . 8 ⊢ ((𝐹:𝑌–1-1-onto→𝑋 ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → ((𝐹‘𝑢) = (𝐹‘𝑣) ↔ 𝑢 = 𝑣))
39	38	adantll 726	. . . . . . 7 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → ((𝐹‘𝑢) = (𝐹‘𝑣) ↔ 𝑢 = 𝑣))
40	23, 35, 39	3bitrd 308	. . . . . 6 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → ((𝑢𝑁𝑣) = 0 ↔ 𝑢 = 𝑣))
41		ffvelcdm 7076	. . . . . . . . . . . . . . 15 ⊢ ((𝐹:𝑌⟶𝑋 ∧ 𝑤 ∈ 𝑌) → (𝐹‘𝑤) ∈ 𝑋)
42	41	ex 417	. . . . . . . . . . . . . 14 ⊢ (𝐹:𝑌⟶𝑋 → (𝑤 ∈ 𝑌 → (𝐹‘𝑤) ∈ 𝑋))
43	28, 42	anim12d 620	. . . . . . . . . . . . 13 ⊢ (𝐹:𝑌⟶𝑋 → (((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌) → (((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) ∧ (𝐹‘𝑤) ∈ 𝑋)))
44	1, 43	syl 18	. . . . . . . . . . . 12 ⊢ (𝐹:𝑌–1-1-onto→𝑋 → (((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌) → (((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) ∧ (𝐹‘𝑤) ∈ 𝑋)))
45	44	imp 411	. . . . . . . . . . 11 ⊢ ((𝐹:𝑌–1-1-onto→𝑋 ∧ ((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌)) → (((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) ∧ (𝐹‘𝑤) ∈ 𝑋))
46	45	adantll 726	. . . . . . . . . 10 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ ((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌)) → (((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) ∧ (𝐹‘𝑤) ∈ 𝑋))
47		mettri2 24507	. . . . . . . . . . . . . . 15 ⊢ ((𝑀 ∈ (Met‘𝑋) ∧ ((𝐹‘𝑤) ∈ 𝑋 ∧ (𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋)) → ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣))))
48	47	expcom 418	. . . . . . . . . . . . . 14 ⊢ (((𝐹‘𝑤) ∈ 𝑋 ∧ (𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) → (𝑀 ∈ (Met‘𝑋) → ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))))
49	48	3expb 1138	. . . . . . . . . . . . 13 ⊢ (((𝐹‘𝑤) ∈ 𝑋 ∧ ((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋)) → (𝑀 ∈ (Met‘𝑋) → ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))))
50	49	ancoms 463	. . . . . . . . . . . 12 ⊢ ((((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) ∧ (𝐹‘𝑤) ∈ 𝑋) → (𝑀 ∈ (Met‘𝑋) → ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))))
51	50	impcom 412	. . . . . . . . . . 11 ⊢ ((𝑀 ∈ (Met‘𝑋) ∧ (((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) ∧ (𝐹‘𝑤) ∈ 𝑋)) → ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣))))
52	51	adantlr 727	. . . . . . . . . 10 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (((𝐹‘𝑢) ∈ 𝑋 ∧ (𝐹‘𝑣) ∈ 𝑋) ∧ (𝐹‘𝑤) ∈ 𝑋)) → ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣))))
53	46, 52	syldan 602	. . . . . . . . 9 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ ((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌)) → ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣))))
54	53	anassrs 472	. . . . . . . 8 ⊢ ((((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) ∧ 𝑤 ∈ 𝑌) → ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣))))
55	21	adantr 485	. . . . . . . . . 10 ⊢ (((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌) → (𝑢𝑁𝑣) = ((𝐹‘𝑢)𝑀(𝐹‘𝑣)))
56		fveq2 6881	. . . . . . . . . . . . . . 15 ⊢ (𝑥 = 𝑤 → (𝐹‘𝑥) = (𝐹‘𝑤))
57	56	oveq1d 7425	. . . . . . . . . . . . . 14 ⊢ (𝑥 = 𝑤 → ((𝐹‘𝑥)𝑀(𝐹‘𝑦)) = ((𝐹‘𝑤)𝑀(𝐹‘𝑦)))
58		fveq2 6881	. . . . . . . . . . . . . . 15 ⊢ (𝑦 = 𝑢 → (𝐹‘𝑦) = (𝐹‘𝑢))
59	58	oveq2d 7426	. . . . . . . . . . . . . 14 ⊢ (𝑦 = 𝑢 → ((𝐹‘𝑤)𝑀(𝐹‘𝑦)) = ((𝐹‘𝑤)𝑀(𝐹‘𝑢)))
60		ovex 7443	. . . . . . . . . . . . . 14 ⊢ ((𝐹‘𝑤)𝑀(𝐹‘𝑢)) ∈ V
61	57, 59, 13, 60	ovmpo 7570	. . . . . . . . . . . . 13 ⊢ ((𝑤 ∈ 𝑌 ∧ 𝑢 ∈ 𝑌) → (𝑤𝑁𝑢) = ((𝐹‘𝑤)𝑀(𝐹‘𝑢)))
62	61	ancoms 463	. . . . . . . . . . . 12 ⊢ ((𝑢 ∈ 𝑌 ∧ 𝑤 ∈ 𝑌) → (𝑤𝑁𝑢) = ((𝐹‘𝑤)𝑀(𝐹‘𝑢)))
63	62	adantlr 727	. . . . . . . . . . 11 ⊢ (((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌) → (𝑤𝑁𝑢) = ((𝐹‘𝑤)𝑀(𝐹‘𝑢)))
64	18	oveq2d 7426	. . . . . . . . . . . . . 14 ⊢ (𝑦 = 𝑣 → ((𝐹‘𝑤)𝑀(𝐹‘𝑦)) = ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))
65		ovex 7443	. . . . . . . . . . . . . 14 ⊢ ((𝐹‘𝑤)𝑀(𝐹‘𝑣)) ∈ V
66	57, 64, 13, 65	ovmpo 7570	. . . . . . . . . . . . 13 ⊢ ((𝑤 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) → (𝑤𝑁𝑣) = ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))
67	66	ancoms 463	. . . . . . . . . . . 12 ⊢ ((𝑣 ∈ 𝑌 ∧ 𝑤 ∈ 𝑌) → (𝑤𝑁𝑣) = ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))
68	67	adantll 726	. . . . . . . . . . 11 ⊢ (((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌) → (𝑤𝑁𝑣) = ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))
69	63, 68	oveq12d 7428	. . . . . . . . . 10 ⊢ (((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌) → ((𝑤𝑁𝑢) + (𝑤𝑁𝑣)) = (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣))))
70	55, 69	breq12d 5122	. . . . . . . . 9 ⊢ (((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) ∧ 𝑤 ∈ 𝑌) → ((𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣)) ↔ ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))))
71	70	adantll 726	. . . . . . . 8 ⊢ ((((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) ∧ 𝑤 ∈ 𝑌) → ((𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣)) ↔ ((𝐹‘𝑢)𝑀(𝐹‘𝑣)) ≤ (((𝐹‘𝑤)𝑀(𝐹‘𝑢)) + ((𝐹‘𝑤)𝑀(𝐹‘𝑣)))))
72	54, 71	mpbird 260	. . . . . . 7 ⊢ ((((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) ∧ 𝑤 ∈ 𝑌) → (𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣)))
73	72	ralrimiva 3157	. . . . . 6 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → ∀𝑤 ∈ 𝑌 (𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣)))
74	40, 73	jca 520	. . . . 5 ⊢ (((𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → (((𝑢𝑁𝑣) = 0 ↔ 𝑢 = 𝑣) ∧ ∀𝑤 ∈ 𝑌 (𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣))))
75	74	3adantl1 1185	. . . 4 ⊢ (((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) ∧ (𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌)) → (((𝑢𝑁𝑣) = 0 ↔ 𝑢 = 𝑣) ∧ ∀𝑤 ∈ 𝑌 (𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣))))
76	75	ex 417	. . 3 ⊢ ((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → ((𝑢 ∈ 𝑌 ∧ 𝑣 ∈ 𝑌) → (((𝑢𝑁𝑣) = 0 ↔ 𝑢 = 𝑣) ∧ ∀𝑤 ∈ 𝑌 (𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣)))))
77	76	ralrimivv 3206	. 2 ⊢ ((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → ∀𝑢 ∈ 𝑌 ∀𝑣 ∈ 𝑌 (((𝑢𝑁𝑣) = 0 ↔ 𝑢 = 𝑣) ∧ ∀𝑤 ∈ 𝑌 (𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣))))
78		ismet 24489	. . 3 ⊢ (𝑌 ∈ 𝐴 → (𝑁 ∈ (Met‘𝑌) ↔ (𝑁:(𝑌 × 𝑌)⟶ℝ ∧ ∀𝑢 ∈ 𝑌 ∀𝑣 ∈ 𝑌 (((𝑢𝑁𝑣) = 0 ↔ 𝑢 = 𝑣) ∧ ∀𝑤 ∈ 𝑌 (𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣))))))
79	78	3ad2ant1 1151	. 2 ⊢ ((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → (𝑁 ∈ (Met‘𝑌) ↔ (𝑁:(𝑌 × 𝑌)⟶ℝ ∧ ∀𝑢 ∈ 𝑌 ∀𝑣 ∈ 𝑌 (((𝑢𝑁𝑣) = 0 ↔ 𝑢 = 𝑣) ∧ ∀𝑤 ∈ 𝑌 (𝑢𝑁𝑣) ≤ ((𝑤𝑁𝑢) + (𝑤𝑁𝑣))))))
80	15, 77, 79	mpbir2and 725	1 ⊢ ((𝑌 ∈ 𝐴 ∧ 𝑀 ∈ (Met‘𝑋) ∧ 𝐹:𝑌–1-1-onto→𝑋) → 𝑁 ∈ (Met‘𝑌))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 400   ∧ w3a 1103   = wceq 1570   ∈ wcel 2143  ∀wral 3079   class class class wbr 5109   × cxp 5659  ⟶wf 6532  –1-1→wf1 6533  –1-1-onto→wf1o 6535  ‘cfv 6536  (class class class)co 7410   ∈ cmpo 7412  ℝcr 11103  0cc0 11104   + caddc 11107   ≤ cle 11248  Metcmet 21517

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1825  ax-4 1839  ax-5 1940  ax-6 1997  ax-7 2038  ax-8 2145  ax-9 2153  ax-10 2176  ax-11 2192  ax-12 2213  ax-ext 2735  ax-sep 5257  ax-nul 5269  ax-pow 5336  ax-pr 5404  ax-un 7732  ax-cnex 11160  ax-resscn 11161  ax-1cn 11162  ax-icn 11163  ax-addcl 11164  ax-mulcl 11166  ax-i2m1 11172

This proof depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1810  df-nf 1814  df-sb 2097  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2838  df-nfc 2912  df-ne 2959  df-nel 3065  df-ral 3080  df-rex 3090  df-rab 3417  df-v 3457  df-sbc 3745  df-csb 3854  df-dif 3908  df-un 3910  df-in 3912  df-ss 3922  df-nul 4287  df-if 4488  df-pw 4564  df-sn 4590  df-pr 4592  df-op 4596  df-uni 4873  df-iun 4958  df-br 5110  df-opab 5174  df-mpt 5193  df-id 5556  df-xp 5667  df-rel 5668  df-cnv 5669  df-co 5670  df-dm 5671  df-rn 5672  df-res 5673  df-ima 5674  df-iota 6492  df-fun 6538  df-fn 6539  df-f 6540  df-f1 6541  df-fo 6542  df-f1o 6543  df-fv 6544  df-ov 7413  df-oprab 7414  df-mpo 7415  df-1st 7982  df-2nd 7983  df-er 8690  df-map 8822  df-en 8940  df-dom 8941  df-sdom 8942  df-pnf 11249  df-mnf 11250  df-xr 11251  df-xadd 13142  df-xmet 21524  df-met 21525

This theorem is used by: (None)