| Step | Hyp | Ref | Expression | 
						
							| 1 |  | opprnzr.1 | ⊢ 𝑂  =  ( oppr ‘ 𝑅 ) | 
						
							| 2 | 1 | opprringb | ⊢ ( 𝑅  ∈  Ring  ↔  𝑂  ∈  Ring ) | 
						
							| 3 | 2 | anbi1i | ⊢ ( ( 𝑅  ∈  Ring  ∧  ( 1r ‘ 𝑅 )  ≠  ( 0g ‘ 𝑅 ) )  ↔  ( 𝑂  ∈  Ring  ∧  ( 1r ‘ 𝑅 )  ≠  ( 0g ‘ 𝑅 ) ) ) | 
						
							| 4 |  | eqid | ⊢ ( 1r ‘ 𝑅 )  =  ( 1r ‘ 𝑅 ) | 
						
							| 5 |  | eqid | ⊢ ( 0g ‘ 𝑅 )  =  ( 0g ‘ 𝑅 ) | 
						
							| 6 | 4 5 | isnzr | ⊢ ( 𝑅  ∈  NzRing  ↔  ( 𝑅  ∈  Ring  ∧  ( 1r ‘ 𝑅 )  ≠  ( 0g ‘ 𝑅 ) ) ) | 
						
							| 7 | 1 4 | oppr1 | ⊢ ( 1r ‘ 𝑅 )  =  ( 1r ‘ 𝑂 ) | 
						
							| 8 | 1 5 | oppr0 | ⊢ ( 0g ‘ 𝑅 )  =  ( 0g ‘ 𝑂 ) | 
						
							| 9 | 7 8 | isnzr | ⊢ ( 𝑂  ∈  NzRing  ↔  ( 𝑂  ∈  Ring  ∧  ( 1r ‘ 𝑅 )  ≠  ( 0g ‘ 𝑅 ) ) ) | 
						
							| 10 | 3 6 9 | 3bitr4i | ⊢ ( 𝑅  ∈  NzRing  ↔  𝑂  ∈  NzRing ) |