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Metamath Proof Explorer

Theorem dmuz

Description: Domain of the upper integers function. (Contributed by Glauco Siliprandi, 23-Oct-2021)

Ref Expression
Assertion dmuz dom ℤ≥ = ℤ

Proof

Step Hyp Ref Expression
1 uzf ⊢ ℤ≥ : ℤ ⟶ 𝒫 ℤ
2 1 fdmi ⊢ dom ℤ≥ = ℤ