Metamath Proof Explorer


Theorem fvilbd

Description: A set is a subset of its image under the identity relation. (Contributed by RP, 22-Jul-2020)

Ref Expression
Hypothesis fvilbd.r ⊢ φ → R ∈ V
Assertion fvilbd ⊢ φ → R ⊆ I ⁡ R

Proof

Step Hyp Ref Expression
1 fvilbd.r ⊢ φ → R ∈ V
2 ssid ⊢ R ⊆ R
3 fvi ⊢ R ∈ V → I ⁡ R = R
4 1 3 syl ⊢ φ → I ⁡ R = R
5 2 4 sseqtrrid ⊢ φ → R ⊆ I ⁡ R