| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rng2idlring.r | ⊢ ( 𝜑  →  𝑅  ∈  Rng ) | 
						
							| 2 |  | rng2idlring.i | ⊢ ( 𝜑  →  𝐼  ∈  ( 2Ideal ‘ 𝑅 ) ) | 
						
							| 3 |  | rng2idlring.j | ⊢ 𝐽  =  ( 𝑅  ↾s  𝐼 ) | 
						
							| 4 |  | rng2idlring.u | ⊢ ( 𝜑  →  𝐽  ∈  Ring ) | 
						
							| 5 |  | rng2idlring.b | ⊢ 𝐵  =  ( Base ‘ 𝑅 ) | 
						
							| 6 |  | rng2idlring.t | ⊢  ·   =  ( .r ‘ 𝑅 ) | 
						
							| 7 |  | rng2idlring.1 | ⊢  1   =  ( 1r ‘ 𝐽 ) | 
						
							| 8 |  | eqid | ⊢ ( Base ‘ 𝐽 )  =  ( Base ‘ 𝐽 ) | 
						
							| 9 | 2 3 8 | 2idlelbas | ⊢ ( 𝜑  →  ( ( Base ‘ 𝐽 )  ∈  ( LIdeal ‘ 𝑅 )  ∧  ( Base ‘ 𝐽 )  ∈  ( LIdeal ‘ ( oppr ‘ 𝑅 ) ) ) ) | 
						
							| 10 | 9 | simprd | ⊢ ( 𝜑  →  ( Base ‘ 𝐽 )  ∈  ( LIdeal ‘ ( oppr ‘ 𝑅 ) ) ) | 
						
							| 11 |  | ringrng | ⊢ ( 𝐽  ∈  Ring  →  𝐽  ∈  Rng ) | 
						
							| 12 | 4 11 | syl | ⊢ ( 𝜑  →  𝐽  ∈  Rng ) | 
						
							| 13 | 3 12 | eqeltrrid | ⊢ ( 𝜑  →  ( 𝑅  ↾s  𝐼 )  ∈  Rng ) | 
						
							| 14 | 1 2 13 | rng2idl0 | ⊢ ( 𝜑  →  ( 0g ‘ 𝑅 )  ∈  𝐼 ) | 
						
							| 15 | 2 3 8 | 2idlbas | ⊢ ( 𝜑  →  ( Base ‘ 𝐽 )  =  𝐼 ) | 
						
							| 16 | 14 15 | eleqtrrd | ⊢ ( 𝜑  →  ( 0g ‘ 𝑅 )  ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 17 | 1 10 16 | 3jca | ⊢ ( 𝜑  →  ( 𝑅  ∈  Rng  ∧  ( Base ‘ 𝐽 )  ∈  ( LIdeal ‘ ( oppr ‘ 𝑅 ) )  ∧  ( 0g ‘ 𝑅 )  ∈  ( Base ‘ 𝐽 ) ) ) | 
						
							| 18 | 8 7 | ringidcl | ⊢ ( 𝐽  ∈  Ring  →   1   ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 19 | 4 18 | syl | ⊢ ( 𝜑  →   1   ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 20 | 19 | anim1ci | ⊢ ( ( 𝜑  ∧  𝐴  ∈  𝐵 )  →  ( 𝐴  ∈  𝐵  ∧   1   ∈  ( Base ‘ 𝐽 ) ) ) | 
						
							| 21 |  | eqid | ⊢ ( 0g ‘ 𝑅 )  =  ( 0g ‘ 𝑅 ) | 
						
							| 22 |  | eqid | ⊢ ( LIdeal ‘ ( oppr ‘ 𝑅 ) )  =  ( LIdeal ‘ ( oppr ‘ 𝑅 ) ) | 
						
							| 23 | 21 5 6 22 | rngridlmcl | ⊢ ( ( ( 𝑅  ∈  Rng  ∧  ( Base ‘ 𝐽 )  ∈  ( LIdeal ‘ ( oppr ‘ 𝑅 ) )  ∧  ( 0g ‘ 𝑅 )  ∈  ( Base ‘ 𝐽 ) )  ∧  ( 𝐴  ∈  𝐵  ∧   1   ∈  ( Base ‘ 𝐽 ) ) )  →  (  1   ·  𝐴 )  ∈  ( Base ‘ 𝐽 ) ) | 
						
							| 24 | 17 20 23 | syl2an2r | ⊢ ( ( 𝜑  ∧  𝐴  ∈  𝐵 )  →  (  1   ·  𝐴 )  ∈  ( Base ‘ 𝐽 ) ) |