Theorem fvproj 8157

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 7427	. 2 ⊢ (𝑋𝐻𝑌) = (𝐻‘⟨𝑋, 𝑌⟩)
2		fvproj.x	. . 3 ⊢ (𝜑 → 𝑋 ∈ 𝐴)
3		fvproj.y	. . 3 ⊢ (𝜑 → 𝑌 ∈ 𝐵)
4		fveq2 6890	. . . . 5 ⊢ (𝑎 = 𝑋 → (𝐹‘𝑎) = (𝐹‘𝑋))
5	4	opeq1d 4845	. . . 4 ⊢ (𝑎 = 𝑋 → ⟨(𝐹‘𝑎), (𝐺‘𝑏)⟩ = ⟨(𝐹‘𝑋), (𝐺‘𝑏)⟩)
6		fveq2 6890	. . . . 5 ⊢ (𝑏 = 𝑌 → (𝐺‘𝑏) = (𝐺‘𝑌))
7	6	opeq2d 4846	. . . 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 6890	. . . . . . 7 ⊢ (𝑥 = 𝑎 → (𝐹‘𝑥) = (𝐹‘𝑎))
10	9	opeq1d 4845	. . . . . 6 ⊢ (𝑥 = 𝑎 → ⟨(𝐹‘𝑥), (𝐺‘𝑦)⟩ = ⟨(𝐹‘𝑎), (𝐺‘𝑦)⟩)
11		fveq2 6890	. . . . . . 7 ⊢ (𝑦 = 𝑏 → (𝐺‘𝑦) = (𝐺‘𝑏))
12	11	opeq2d 4846	. . . . . 6 ⊢ (𝑦 = 𝑏 → ⟨(𝐹‘𝑎), (𝐺‘𝑦)⟩ = ⟨(𝐹‘𝑎), (𝐺‘𝑏)⟩)
13	10, 12	cbvmpov 7519	. . . . 5 ⊢ (𝑥 ∈ 𝐴, 𝑦 ∈ 𝐵 ↦ ⟨(𝐹‘𝑥), (𝐺‘𝑦)⟩) = (𝑎 ∈ 𝐴, 𝑏 ∈ 𝐵 ↦ ⟨(𝐹‘𝑎), (𝐺‘𝑏)⟩)
14	8, 13	eqtri 2783	. . . 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 7584	. . 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 2809	1 ⊢ (𝜑 → (𝐻‘⟨𝑋, 𝑌⟩) = ⟨(𝐹‘𝑋), (𝐺‘𝑌)⟩)

This proof depends on syntax axioms:   → wi 4   = wceq 1569   ∈ wcel 2144  ⟨cop 4834  ‘cfv 6543  (class class class)co 7424   ∈ cmpo 7426

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-8 2146  ax-9 2154  ax-10 2177  ax-11 2193  ax-12 2212  ax-ext 2732  ax-sep 5248  ax-pr 5391

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1572  df-fal 1582  df-ex 1812  df-nf 1816  df-sb 2099  df-mo 2564  df-eu 2594  df-clab 2739  df-cleq 2752  df-clel 2835  df-nfc 2909  df-ral 3077  df-rex 3087  df-rab 3413  df-v 3452  df-sbc 3739  df-ss 3897  df-dif 4046  df-in 4090  df-un 4150  df-nul 4278  df-if 4482  df-sn 4585  df-pr 4587  df-op 4835  df-uni 4867  df-br 5103  df-opab 5167  df-id 5546  df-xp 5657  df-rel 5658  df-cnv 5659  df-co 5660  df-dm 5661  df-iota 6497  df-fun 6545  df-fv 6551  df-ov 7427  df-oprab 7428  df-mpo 7429

This theorem is used by:  fimaproj  8158  ex-fpar  31072  qtophaus  34518