Theorem reli 2500

Description: The identity relation is a relation. Part of Exercise 4.12(p) of [Mendelson] p. 235.

Assertion

Ref	Expression
reli	⊢ Rel I

Proof of Theorem reli

Step	Hyp	Ref	Expression
1		relopab 2494	. 2 ⊢ Rel {⟨x, y⟩∣x = y}
2		df-id 2125	. . 3 ⊢ I = {⟨x, y⟩∣x = y}
3		releq 2477	. . 3 ⊢ (I = {⟨x, y⟩∣x = y} → (Rel I ↔ Rel {⟨x, y⟩∣x = y}))
4	2, 3	ax-mp 6	. 2 ⊢ (Rel I ↔ Rel {⟨x, y⟩∣x = y})
5	1, 4	mpbir 165	1 ⊢ Rel I

Syntax hints:   ↔ wb 127   = weq 797   = wceq 1091  {copab 2055  Icid 2057  Rel wrel 2415

This theorem is referenced by:  iss 2599  intirr 2628  cnvi 2634  funi 2692  f1ovi 2826  idssen 3309

This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-13 804  ax-14 805  ax-16 922  ax-17 925  ax-ext 1074  ax-rep 1075  ax-pow 1077

This theorem depends on definitions:  df-bi 128  df-or 197  df-an 198  df-ex 679  df-sb 853  df-clab 1093  df-cleq 1097  df-clel 1099  df-v 1349  df-dif 1489  df-un 1490  df-in 1491  df-ss 1492  df-nul 1708  df-pw 1799  df-sn 1811  df-pr 1812  df-op 1815  df-opab 2098  df-id 2125  df-xp 2424  df-rel 2425

metamath.org