Theorem relssr 39257

Description: The subset relation is a relation. (Contributed by Peter Mazsa, 1-Aug-2019.)

Assertion

Ref	Expression
relssr	⊢ Rel S

Proof of Theorem relssr

Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-ssr 39255	. 2 ⊢ S = {⟨𝑥, 𝑦⟩ ∣ 𝑥 ⊆ 𝑦}
2	1	relopabiv 5807	1 ⊢ Rel S

This proof depends on syntax axioms:   ⊆ wss 3905  Rel wrel 5666   S cssr 38863

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-ext 2735

This proof depends on definitions:  df-bi 210  df-an 401  df-tru 1573  df-ex 1810  df-sb 2097  df-clab 2742  df-cleq 2755  df-clel 2838  df-v 3457  df-ss 3922  df-opab 5174  df-xp 5667  df-rel 5668  df-ssr 39255

This theorem is used by:  brssr  39258  issetssr  39260  brcnvssr  39263  extssr  39266