Theorem relresfld 6277

Description: Restriction of a relation to its field. (Contributed by FL, 15-Apr-2012.) (Proof shortened by Eric Schmidt, 16-Aug-2026.)

Assertion

Ref	Expression
relresfld	⊢ (Rel 𝑅 → (𝑅 ↾ ∪ ∪ 𝑅) = 𝑅)

Proof of Theorem relresfld

Step	Hyp	Ref	Expression
1		relfld 6276	. . 3 ⊢ (Rel 𝑅 → ∪ ∪ 𝑅 = (dom 𝑅 ∪ ran 𝑅))
2	1	reseq2d 5976	. 2 ⊢ (Rel 𝑅 → (𝑅 ↾ ∪ ∪ 𝑅) = (𝑅 ↾ (dom 𝑅 ∪ ran 𝑅)))
3		ssun1 4127	. . 3 ⊢ dom 𝑅 ⊆ (dom 𝑅 ∪ ran 𝑅)
4		relssres 6019	. . 3 ⊢ ((Rel 𝑅 ∧ dom 𝑅 ⊆ (dom 𝑅 ∪ ran 𝑅)) → (𝑅 ↾ (dom 𝑅 ∪ ran 𝑅)) = 𝑅)
5	3, 4	mpan2 704	. 2 ⊢ (Rel 𝑅 → (𝑅 ↾ (dom 𝑅 ∪ ran 𝑅)) = 𝑅)
6	2, 5	eqtrd 2797	1 ⊢ (Rel 𝑅 → (𝑅 ↾ ∪ ∪ 𝑅) = 𝑅)

This proof depends on syntax axioms:   → wi 4   = wceq 1570   ∪ cun 3900   ⊆ wss 3902  ∪ cuni 4870  dom cdm 5659  ran crn 5660   ↾ cres 5661  Rel wrel 5664

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-ext 2734  ax-sep 5255  ax-pr 5402

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-sb 2100  df-clab 2741  df-cleq 2754  df-clel 2837  df-ral 3079  df-rex 3089  df-rab 3415  df-v 3455  df-dif 3905  df-un 3907  df-in 3909  df-ss 3919  df-nul 4283  df-if 4486  df-pw 4562  df-sn 4588  df-pr 4590  df-op 4594  df-uni 4871  df-br 5108  df-opab 5172  df-xp 5665  df-rel 5666  df-cnv 5667  df-dm 5669  df-rn 5670  df-res 5671

This theorem is used by:  relcoi1  6280