Metamath Proof Explorer


Theorem metpsmet

Description: A metric is a pseudometric. (Contributed by Glauco Siliprandi, 8-Apr-2021)

Ref Expression
Assertion metpsmet ( 𝐷 ∈ ( Met ‘ 𝑋 ) → 𝐷 ∈ ( PsMet ‘ 𝑋 ) )

Proof

Step Hyp Ref Expression
1 metxmet ( 𝐷 ∈ ( Met ‘ 𝑋 ) → 𝐷 ∈ ( ∞Met ‘ 𝑋 ) )
2 xmetpsmet ( 𝐷 ∈ ( ∞Met ‘ 𝑋 ) → 𝐷 ∈ ( PsMet ‘ 𝑋 ) )
3 1 2 syl ( 𝐷 ∈ ( Met ‘ 𝑋 ) → 𝐷 ∈ ( PsMet ‘ 𝑋 ) )