| Step | Hyp | Ref | Expression | 
						
							| 1 |  | opprsubrng.o | ⊢ 𝑂  =  ( oppr ‘ 𝑅 ) | 
						
							| 2 |  | subrngrcl | ⊢ ( 𝑥  ∈  ( SubRng ‘ 𝑅 )  →  𝑅  ∈  Rng ) | 
						
							| 3 |  | subrngrcl | ⊢ ( 𝑥  ∈  ( SubRng ‘ 𝑂 )  →  𝑂  ∈  Rng ) | 
						
							| 4 | 1 | opprrngb | ⊢ ( 𝑅  ∈  Rng  ↔  𝑂  ∈  Rng ) | 
						
							| 5 | 3 4 | sylibr | ⊢ ( 𝑥  ∈  ( SubRng ‘ 𝑂 )  →  𝑅  ∈  Rng ) | 
						
							| 6 | 1 | opprsubg | ⊢ ( SubGrp ‘ 𝑅 )  =  ( SubGrp ‘ 𝑂 ) | 
						
							| 7 | 6 | a1i | ⊢ ( 𝑅  ∈  Rng  →  ( SubGrp ‘ 𝑅 )  =  ( SubGrp ‘ 𝑂 ) ) | 
						
							| 8 | 7 | eleq2d | ⊢ ( 𝑅  ∈  Rng  →  ( 𝑥  ∈  ( SubGrp ‘ 𝑅 )  ↔  𝑥  ∈  ( SubGrp ‘ 𝑂 ) ) ) | 
						
							| 9 |  | ralcom | ⊢ ( ∀ 𝑧  ∈  𝑥 ∀ 𝑦  ∈  𝑥 ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝑥  ↔  ∀ 𝑦  ∈  𝑥 ∀ 𝑧  ∈  𝑥 ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝑥 ) | 
						
							| 10 |  | eqid | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑅 ) | 
						
							| 11 |  | eqid | ⊢ ( .r ‘ 𝑅 )  =  ( .r ‘ 𝑅 ) | 
						
							| 12 |  | eqid | ⊢ ( .r ‘ 𝑂 )  =  ( .r ‘ 𝑂 ) | 
						
							| 13 | 10 11 1 12 | opprmul | ⊢ ( 𝑦 ( .r ‘ 𝑂 ) 𝑧 )  =  ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 ) | 
						
							| 14 | 13 | eleq1i | ⊢ ( ( 𝑦 ( .r ‘ 𝑂 ) 𝑧 )  ∈  𝑥  ↔  ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝑥 ) | 
						
							| 15 | 14 | 2ralbii | ⊢ ( ∀ 𝑦  ∈  𝑥 ∀ 𝑧  ∈  𝑥 ( 𝑦 ( .r ‘ 𝑂 ) 𝑧 )  ∈  𝑥  ↔  ∀ 𝑦  ∈  𝑥 ∀ 𝑧  ∈  𝑥 ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝑥 ) | 
						
							| 16 | 9 15 | bitr4i | ⊢ ( ∀ 𝑧  ∈  𝑥 ∀ 𝑦  ∈  𝑥 ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝑥  ↔  ∀ 𝑦  ∈  𝑥 ∀ 𝑧  ∈  𝑥 ( 𝑦 ( .r ‘ 𝑂 ) 𝑧 )  ∈  𝑥 ) | 
						
							| 17 | 16 | a1i | ⊢ ( 𝑅  ∈  Rng  →  ( ∀ 𝑧  ∈  𝑥 ∀ 𝑦  ∈  𝑥 ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝑥  ↔  ∀ 𝑦  ∈  𝑥 ∀ 𝑧  ∈  𝑥 ( 𝑦 ( .r ‘ 𝑂 ) 𝑧 )  ∈  𝑥 ) ) | 
						
							| 18 | 8 17 | anbi12d | ⊢ ( 𝑅  ∈  Rng  →  ( ( 𝑥  ∈  ( SubGrp ‘ 𝑅 )  ∧  ∀ 𝑧  ∈  𝑥 ∀ 𝑦  ∈  𝑥 ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝑥 )  ↔  ( 𝑥  ∈  ( SubGrp ‘ 𝑂 )  ∧  ∀ 𝑦  ∈  𝑥 ∀ 𝑧  ∈  𝑥 ( 𝑦 ( .r ‘ 𝑂 ) 𝑧 )  ∈  𝑥 ) ) ) | 
						
							| 19 | 10 11 | issubrng2 | ⊢ ( 𝑅  ∈  Rng  →  ( 𝑥  ∈  ( SubRng ‘ 𝑅 )  ↔  ( 𝑥  ∈  ( SubGrp ‘ 𝑅 )  ∧  ∀ 𝑧  ∈  𝑥 ∀ 𝑦  ∈  𝑥 ( 𝑧 ( .r ‘ 𝑅 ) 𝑦 )  ∈  𝑥 ) ) ) | 
						
							| 20 | 1 10 | opprbas | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑂 ) | 
						
							| 21 | 20 12 | issubrng2 | ⊢ ( 𝑂  ∈  Rng  →  ( 𝑥  ∈  ( SubRng ‘ 𝑂 )  ↔  ( 𝑥  ∈  ( SubGrp ‘ 𝑂 )  ∧  ∀ 𝑦  ∈  𝑥 ∀ 𝑧  ∈  𝑥 ( 𝑦 ( .r ‘ 𝑂 ) 𝑧 )  ∈  𝑥 ) ) ) | 
						
							| 22 | 4 21 | sylbi | ⊢ ( 𝑅  ∈  Rng  →  ( 𝑥  ∈  ( SubRng ‘ 𝑂 )  ↔  ( 𝑥  ∈  ( SubGrp ‘ 𝑂 )  ∧  ∀ 𝑦  ∈  𝑥 ∀ 𝑧  ∈  𝑥 ( 𝑦 ( .r ‘ 𝑂 ) 𝑧 )  ∈  𝑥 ) ) ) | 
						
							| 23 | 18 19 22 | 3bitr4d | ⊢ ( 𝑅  ∈  Rng  →  ( 𝑥  ∈  ( SubRng ‘ 𝑅 )  ↔  𝑥  ∈  ( SubRng ‘ 𝑂 ) ) ) | 
						
							| 24 | 2 5 23 | pm5.21nii | ⊢ ( 𝑥  ∈  ( SubRng ‘ 𝑅 )  ↔  𝑥  ∈  ( SubRng ‘ 𝑂 ) ) | 
						
							| 25 | 24 | eqriv | ⊢ ( SubRng ‘ 𝑅 )  =  ( SubRng ‘ 𝑂 ) |