Theorem fvproj 8144

Description: Value of a function on ordered pairs with values expressed as ordered pairs. Note that 𝐹 and 𝐺 are the projections of 𝐻 to the first and second coordinate respectively. (Contributed by Thierry Arnoux, 30-Dec-2019.)

Hypotheses

Ref	Expression
fvproj.h	⊢ 𝐻 = (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐵 ↦ ⟨(𝐹‘𝑥), (𝐺‘𝑦)⟩)
fvproj.x	⊢ (𝜑 → 𝑋 ∈ 𝐴)
fvproj.y	⊢ (𝜑 → 𝑌 ∈ 𝐵)

Assertion

Ref	Expression
fvproj	⊢ (𝜑 → (𝐻‘⟨𝑋, 𝑌⟩) = ⟨(𝐹‘𝑋), (𝐺‘𝑌)⟩)

Distinct variable groups:   𝑥,𝐴,𝑦   𝑥,𝐵,𝑦   𝑥,𝐹,𝑦   𝑥,𝐺,𝑦

Allowed substitution hints:   𝜑(𝑥, 𝑦)   𝐻(𝑥, 𝑦)   𝑋(𝑥, 𝑦)   𝑌(𝑥, 𝑦)

Proof of Theorem fvproj

Dummy variables 𝑎 𝑏 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-ov 7421	. 2 ⊢ (𝑋𝐻𝑌) = (𝐻‘⟨𝑋, 𝑌⟩)
2		fvproj.x	. . 3 ⊢ (𝜑 → 𝑋 ∈ 𝐴)
3		fvproj.y	. . 3 ⊢ (𝜑 → 𝑌 ∈ 𝐵)
4		fveq2 6883	. . . . 5 ⊢ (𝑎 = 𝑋 → (𝐹‘𝑎) = (𝐹‘𝑋))
5	4	opeq1d 4839	. . . 4 ⊢ (𝑎 = 𝑋 → ⟨(𝐹‘𝑎), (𝐺‘𝑏)⟩ = ⟨(𝐹‘𝑋), (𝐺‘𝑏)⟩)
6		fveq2 6883	. . . . 5 ⊢ (𝑏 = 𝑌 → (𝐺‘𝑏) = (𝐺‘𝑌))
7	6	opeq2d 4840	. . . 4 ⊢ (𝑏 = 𝑌 → ⟨(𝐹‘𝑋), (𝐺‘𝑏)⟩ = ⟨(𝐹‘𝑋), (𝐺‘𝑌)⟩)
8		fvproj.h	. . . . 5 ⊢ 𝐻 = (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐵 ↦ ⟨(𝐹‘𝑥), (𝐺‘𝑦)⟩)
9		fveq2 6883	. . . . . . 7 ⊢ (𝑥 = 𝑎 → (𝐹‘𝑥) = (𝐹‘𝑎))
10	9	opeq1d 4839	. . . . . 6 ⊢ (𝑥 = 𝑎 → ⟨(𝐹‘𝑥), (𝐺‘𝑦)⟩ = ⟨(𝐹‘𝑎), (𝐺‘𝑦)⟩)
11		fveq2 6883	. . . . . . 7 ⊢ (𝑦 = 𝑏 → (𝐺‘𝑦) = (𝐺‘𝑏))
12	11	opeq2d 4840	. . . . . 6 ⊢ (𝑦 = 𝑏 → ⟨(𝐹‘𝑎), (𝐺‘𝑦)⟩ = ⟨(𝐹‘𝑎), (𝐺‘𝑏)⟩)
13	10, 12	cbvmpov 7513	. . . . 5 ⊢ (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐵 ↦ ⟨(𝐹‘𝑥), (𝐺‘𝑦)⟩) = (𝑎 ∈ 𝐴, 𝑏 ∈ 𝐵 ↦ ⟨(𝐹‘𝑎), (𝐺‘𝑏)⟩)
14	8, 13	eqtri 2784	. . . 4 ⊢ 𝐻 = (𝑎 ∈ 𝐴, 𝑏 ∈ 𝐵 ↦ ⟨(𝐹‘𝑎), (𝐺‘𝑏)⟩)
15		opex 5432	. . . 4 ⊢ ⟨(𝐹‘𝑋), (𝐺‘𝑌)⟩ ∈ V
16	5, 7, 14, 15	ovmpo 7578	. . 3 ⊢ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → (𝑋𝐻𝑌) = ⟨(𝐹‘𝑋), (𝐺‘𝑌)⟩)
17	2, 3, 16	syl2anc 596	. 2 ⊢ (𝜑 → (𝑋𝐻𝑌) = ⟨(𝐹‘𝑋), (𝐺‘𝑌)⟩)
18	1, 17	eqtr3id 2810	1 ⊢ (𝜑 → (𝐻‘⟨𝑋, 𝑌⟩) = ⟨(𝐹‘𝑋), (𝐺‘𝑌)⟩)

This proof depends on syntax axioms:   → wi 4   = wceq 1570   ∈ wcel 2145  ⟨cop 4590  ‘cfv 6537  (class class class)co 7418   ∈ cmpo 7420

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-10 2178  ax-11 2194  ax-12 2213  ax-ext 2733  ax-sep 5249  ax-pr 5391

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-mo 2565  df-eu 2595  df-clab 2740  df-cleq 2753  df-clel 2836  df-nfc 2910  df-ral 3078  df-rex 3088  df-rab 3414  df-v 3453  df-sbc 3740  df-dif 3902  df-un 3904  df-in 3906  df-ss 3916  df-nul 4280  df-if 4483  df-sn 4585  df-pr 4587  df-op 4591  df-uni 4868  df-br 5104  df-opab 5168  df-id 5546  df-xp 5657  df-rel 5658  df-cnv 5659  df-co 5660  df-dm 5661  df-iota 6493  df-fun 6539  df-fv 6545  df-ov 7421  df-oprab 7422  df-mpo 7423

This theorem is used by:  fimaproj  8145  ex-fpar  31056  qtophaus  34461