Metamath Proof Explorer


Theorem resiexd

Description: The restriction of the identity relation to a set is a set. (Contributed by AV, 15-Feb-2020)

Ref Expression
Hypothesis resiexd.b ⊢ ( 𝜑 → 𝐵 ∈ 𝑉 )
Assertion resiexd ( 𝜑 → ( I ↾ 𝐵 ) ∈ V )

Proof

Step Hyp Ref Expression
1 resiexd.b ⊢ ( 𝜑 → 𝐵 ∈ 𝑉 )
2 funi ⊢ Fun I
3 resfunexg ⊢ ( ( Fun I ∧ 𝐵 ∈ 𝑉 ) → ( I ↾ 𝐵 ) ∈ V )
4 2 1 3 sylancr ⊢ ( 𝜑 → ( I ↾ 𝐵 ) ∈ V )