Metamath Proof Explorer


Theorem 1zzd

Description: One is an integer, deduction form. (Contributed by David A. Wheeler, 6-Dec-2018)

Ref Expression
Assertion 1zzd ( 𝜑 → 1 ∈ ℤ )

Proof

Step Hyp Ref Expression
1 1z 1 ∈ ℤ
2 1 a1i ( 𝜑 → 1 ∈ ℤ )