Theorem sscrel 17846

Description: The subcategory subset relation is a relation. (Contributed by Mario Carneiro, 6-Jan-2017.)

Assertion

Ref	Expression
sscrel	⊢ Rel ⊆cat

Proof of Theorem sscrel

Dummy variables ℎ 𝑗 𝑠 𝑡 𝑥 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-ssc 17843	. 2 ⊢ ⊆cat = {⟨ℎ, 𝑗⟩ ∣ ∃𝑡(𝑗 Fn (𝑡 × 𝑡) ∧ ∃𝑠 ∈ 𝒫 𝑡ℎ ∈ X𝑥 ∈ (𝑠 × 𝑠)𝒫 (𝑗‘𝑥))}
2	1	relopabiv 5793	1 ⊢ Rel ⊆cat

Syntax hints:   ∧ wa 399  ∃wex 1799   ∈ wcel 2142  ∃wrex 3086  𝒫 cpw 4555   × cxp 5645  Rel wrel 5652   Fn wfn 6516  ‘cfv 6521  Xcixp 8879   ⊆_cat cssc 17840

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1815  ax-4 1829  ax-5 1930  ax-6 1987  ax-7 2028  ax-8 2144  ax-9 2152  ax-ext 2734

This theorem depends on definitions:  df-bi 209  df-an 400  df-tru 1563  df-ex 1800  df-sb 2091  df-clab 2741  df-cleq 2754  df-clel 2837  df-v 3456  df-ss 3921  df-opab 5163  df-xp 5653  df-rel 5654  df-ssc 17843

This theorem is referenced by:  brssc  17847  ssc1  17854  ssc2  17855  ssctr  17858  issubc  17868  iinfssc  49678