ℤ A ring contains ℤ or ℤ𝑛 Let 𝑅 be a ring. Then 𝑅 has a unique subring isomorphic to ℤ or modular arithmetic ℤ𝑛 #m/thm/ring given by the image of the unique homomorphism 𝐼 :ℤ →𝑅. ProofSince 𝐼(ℤ) ≅ℤ/ker𝐼 and ker𝐼 =𝑛ℤ where 𝑛 is the characteristic of 𝑅. #state/tidy | #lang/en | #SemBr