| Step | Hyp | Ref | Expression | 
						
							| 1 |  | opprbas.1 | ⊢ 𝑂  =  ( oppr ‘ 𝑅 ) | 
						
							| 2 |  | ringrng | ⊢ ( 𝑅  ∈  Ring  →  𝑅  ∈  Rng ) | 
						
							| 3 | 1 | opprrng | ⊢ ( 𝑅  ∈  Rng  →  𝑂  ∈  Rng ) | 
						
							| 4 | 2 3 | syl | ⊢ ( 𝑅  ∈  Ring  →  𝑂  ∈  Rng ) | 
						
							| 5 |  | oveq1 | ⊢ ( 𝑧  =  ( 1r ‘ 𝑅 )  →  ( 𝑧 ( .r ‘ 𝑂 ) 𝑥 )  =  ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑂 ) 𝑥 ) ) | 
						
							| 6 | 5 | eqeq1d | ⊢ ( 𝑧  =  ( 1r ‘ 𝑅 )  →  ( ( 𝑧 ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥  ↔  ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥 ) ) | 
						
							| 7 | 6 | ovanraleqv | ⊢ ( 𝑧  =  ( 1r ‘ 𝑅 )  →  ( ∀ 𝑥  ∈  ( Base ‘ 𝑅 ) ( ( 𝑧 ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥  ∧  ( 𝑥 ( .r ‘ 𝑂 ) 𝑧 )  =  𝑥 )  ↔  ∀ 𝑥  ∈  ( Base ‘ 𝑅 ) ( ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥  ∧  ( 𝑥 ( .r ‘ 𝑂 ) ( 1r ‘ 𝑅 ) )  =  𝑥 ) ) ) | 
						
							| 8 |  | eqid | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑅 ) | 
						
							| 9 |  | eqid | ⊢ ( 1r ‘ 𝑅 )  =  ( 1r ‘ 𝑅 ) | 
						
							| 10 | 8 9 | ringidcl | ⊢ ( 𝑅  ∈  Ring  →  ( 1r ‘ 𝑅 )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 11 |  | eqid | ⊢ ( .r ‘ 𝑅 )  =  ( .r ‘ 𝑅 ) | 
						
							| 12 |  | eqid | ⊢ ( .r ‘ 𝑂 )  =  ( .r ‘ 𝑂 ) | 
						
							| 13 | 8 11 1 12 | opprmul | ⊢ ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑂 ) 𝑥 )  =  ( 𝑥 ( .r ‘ 𝑅 ) ( 1r ‘ 𝑅 ) ) | 
						
							| 14 | 8 11 9 | ringridm | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( 𝑥 ( .r ‘ 𝑅 ) ( 1r ‘ 𝑅 ) )  =  𝑥 ) | 
						
							| 15 | 13 14 | eqtrid | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥 ) | 
						
							| 16 | 8 11 1 12 | opprmul | ⊢ ( 𝑥 ( .r ‘ 𝑂 ) ( 1r ‘ 𝑅 ) )  =  ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑅 ) 𝑥 ) | 
						
							| 17 | 8 11 9 | ringlidm | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑅 ) 𝑥 )  =  𝑥 ) | 
						
							| 18 | 16 17 | eqtrid | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( 𝑥 ( .r ‘ 𝑂 ) ( 1r ‘ 𝑅 ) )  =  𝑥 ) | 
						
							| 19 | 15 18 | jca | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑥  ∈  ( Base ‘ 𝑅 ) )  →  ( ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥  ∧  ( 𝑥 ( .r ‘ 𝑂 ) ( 1r ‘ 𝑅 ) )  =  𝑥 ) ) | 
						
							| 20 | 19 | ralrimiva | ⊢ ( 𝑅  ∈  Ring  →  ∀ 𝑥  ∈  ( Base ‘ 𝑅 ) ( ( ( 1r ‘ 𝑅 ) ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥  ∧  ( 𝑥 ( .r ‘ 𝑂 ) ( 1r ‘ 𝑅 ) )  =  𝑥 ) ) | 
						
							| 21 | 7 10 20 | rspcedvdw | ⊢ ( 𝑅  ∈  Ring  →  ∃ 𝑧  ∈  ( Base ‘ 𝑅 ) ∀ 𝑥  ∈  ( Base ‘ 𝑅 ) ( ( 𝑧 ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥  ∧  ( 𝑥 ( .r ‘ 𝑂 ) 𝑧 )  =  𝑥 ) ) | 
						
							| 22 | 1 8 | opprbas | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑂 ) | 
						
							| 23 | 22 12 | isringrng | ⊢ ( 𝑂  ∈  Ring  ↔  ( 𝑂  ∈  Rng  ∧  ∃ 𝑧  ∈  ( Base ‘ 𝑅 ) ∀ 𝑥  ∈  ( Base ‘ 𝑅 ) ( ( 𝑧 ( .r ‘ 𝑂 ) 𝑥 )  =  𝑥  ∧  ( 𝑥 ( .r ‘ 𝑂 ) 𝑧 )  =  𝑥 ) ) ) | 
						
							| 24 | 4 21 23 | sylanbrc | ⊢ ( 𝑅  ∈  Ring  →  𝑂  ∈  Ring ) |