Metamath Proof Explorer


Theorem pzriprnglem1

Description: Lemma 1 for pzriprng : R is a non-unital (actually a unital!) ring. (Contributed by AV, 17-Mar-2025)

Ref Expression
Hypothesis pzriprng.r 𝑅 = ( ℤring ×sring )
Assertion pzriprnglem1 𝑅 ∈ Rng

Proof

Step Hyp Ref Expression
1 pzriprng.r 𝑅 = ( ℤring ×sring )
2 zringrng ring ∈ Rng
3 id ( ℤring ∈ Rng → ℤring ∈ Rng )
4 1 3 3 xpsrngd ( ℤring ∈ Rng → 𝑅 ∈ Rng )
5 2 4 ax-mp 𝑅 ∈ Rng