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Metamath Proof Explorer

Theorem reli

Description: The identity relation is a relation. Part of Exercise 4.12(p) of Mendelson p. 235. (Contributed by NM, 26-Apr-1998) (Revised by Mario Carneiro, 21-Dec-2013)

		Ref	Expression
	Assertion	reli	$⊢ Rel I$

Proof

Step	Hyp	Ref	Expression
1		df-id	$⊢ I = \{⟨x, y⟩ \| x = y\}$
2	1	relopabiv	$⊢ Rel I$