| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lidlabl.l | ⊢ 𝐿  =  ( LIdeal ‘ 𝑅 ) | 
						
							| 2 |  | lidlabl.i | ⊢ 𝐼  =  ( 𝑅  ↾s  𝑈 ) | 
						
							| 3 |  | zlidlring.b | ⊢ 𝐵  =  ( Base ‘ 𝑅 ) | 
						
							| 4 |  | zlidlring.0 | ⊢  0   =  ( 0g ‘ 𝑅 ) | 
						
							| 5 |  | eqid | ⊢ ( Base ‘ 𝐼 )  =  ( Base ‘ 𝐼 ) | 
						
							| 6 |  | eqid | ⊢ ( .r ‘ 𝐼 )  =  ( .r ‘ 𝐼 ) | 
						
							| 7 | 5 6 | isringrng | ⊢ ( 𝐼  ∈  Ring  ↔  ( 𝐼  ∈  Rng  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 8 |  | domnring | ⊢ ( 𝑅  ∈  Domn  →  𝑅  ∈  Ring ) | 
						
							| 9 | 8 | anim1i | ⊢ ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  →  ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 ) ) | 
						
							| 10 | 1 2 | lidlrng | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  →  𝐼  ∈  Rng ) | 
						
							| 11 | 9 10 | syl | ⊢ ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  →  𝐼  ∈  Rng ) | 
						
							| 12 |  | ibar | ⊢ ( 𝐼  ∈  Rng  →  ( ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ( 𝐼  ∈  Rng  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) ) | 
						
							| 13 | 12 | bicomd | ⊢ ( 𝐼  ∈  Rng  →  ( ( 𝐼  ∈  Rng  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  ↔  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 14 | 13 | adantl | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ( 𝐼  ∈  Rng  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  ↔  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 15 |  | eqid | ⊢ ( .r ‘ 𝑅 )  =  ( .r ‘ 𝑅 ) | 
						
							| 16 | 2 15 | ressmulr | ⊢ ( 𝑈  ∈  𝐿  →  ( .r ‘ 𝑅 )  =  ( .r ‘ 𝐼 ) ) | 
						
							| 17 | 16 | eqcomd | ⊢ ( 𝑈  ∈  𝐿  →  ( .r ‘ 𝐼 )  =  ( .r ‘ 𝑅 ) ) | 
						
							| 18 | 17 | oveqd | ⊢ ( 𝑈  ∈  𝐿  →  ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 ) ) | 
						
							| 19 | 18 | eqeq1d | ⊢ ( 𝑈  ∈  𝐿  →  ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ↔  ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦 ) ) | 
						
							| 20 | 17 | oveqd | ⊢ ( 𝑈  ∈  𝐿  →  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 ) ) | 
						
							| 21 | 20 | eqeq1d | ⊢ ( 𝑈  ∈  𝐿  →  ( ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦  ↔  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 22 | 19 21 | anbi12d | ⊢ ( 𝑈  ∈  𝐿  →  ( ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 23 | 22 | ad2antlr | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 24 | 23 | ad2antrr | ⊢ ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  ( ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 25 | 24 | ralbidv | ⊢ ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  ( ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 26 |  | simp-4l | ⊢ ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  𝑅  ∈  Domn ) | 
						
							| 27 | 1 2 | lidlbas | ⊢ ( 𝑈  ∈  𝐿  →  ( Base ‘ 𝐼 )  =  𝑈 ) | 
						
							| 28 | 27 | eleq1d | ⊢ ( 𝑈  ∈  𝐿  →  ( ( Base ‘ 𝐼 )  ∈  𝐿  ↔  𝑈  ∈  𝐿 ) ) | 
						
							| 29 | 28 | ibir | ⊢ ( 𝑈  ∈  𝐿  →  ( Base ‘ 𝐼 )  ∈  𝐿 ) | 
						
							| 30 | 29 | ad3antlr | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  →  ( Base ‘ 𝐼 )  ∈  𝐿 ) | 
						
							| 31 | 27 | ad2antlr | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( Base ‘ 𝐼 )  =  𝑈 ) | 
						
							| 32 | 31 | eqeq1d | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ( Base ‘ 𝐼 )  =  {  0  }  ↔  𝑈  =  {  0  } ) ) | 
						
							| 33 | 32 | biimpd | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ( Base ‘ 𝐼 )  =  {  0  }  →  𝑈  =  {  0  } ) ) | 
						
							| 34 | 33 | necon3bd | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ¬  𝑈  =  {  0  }  →  ( Base ‘ 𝐼 )  ≠  {  0  } ) ) | 
						
							| 35 | 34 | imp | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  →  ( Base ‘ 𝐼 )  ≠  {  0  } ) | 
						
							| 36 | 30 35 | jca | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  →  ( ( Base ‘ 𝐼 )  ∈  𝐿  ∧  ( Base ‘ 𝐼 )  ≠  {  0  } ) ) | 
						
							| 37 | 36 | adantr | ⊢ ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  ( ( Base ‘ 𝐼 )  ∈  𝐿  ∧  ( Base ‘ 𝐼 )  ≠  {  0  } ) ) | 
						
							| 38 |  | simpr | ⊢ ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  𝑥  ∈  ( Base ‘ 𝐼 ) ) | 
						
							| 39 |  | eqid | ⊢ ( 1r ‘ 𝑅 )  =  ( 1r ‘ 𝑅 ) | 
						
							| 40 | 1 15 39 4 | lidldomn1 | ⊢ ( ( 𝑅  ∈  Domn  ∧  ( ( Base ‘ 𝐼 )  ∈  𝐿  ∧  ( Base ‘ 𝐼 )  ≠  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  ( ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 )  →  𝑥  =  ( 1r ‘ 𝑅 ) ) ) | 
						
							| 41 | 26 37 38 40 | syl3anc | ⊢ ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  ( ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 )  →  𝑥  =  ( 1r ‘ 𝑅 ) ) ) | 
						
							| 42 | 25 41 | sylbid | ⊢ ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  ( ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  →  𝑥  =  ( 1r ‘ 𝑅 ) ) ) | 
						
							| 43 | 42 | imp | ⊢ ( ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  ∧  ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  →  𝑥  =  ( 1r ‘ 𝑅 ) ) | 
						
							| 44 | 27 | ad3antlr | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  →  ( Base ‘ 𝐼 )  =  𝑈 ) | 
						
							| 45 | 44 | eleq2d | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  →  ( 𝑥  ∈  ( Base ‘ 𝐼 )  ↔  𝑥  ∈  𝑈 ) ) | 
						
							| 46 | 45 | biimpd | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  →  ( 𝑥  ∈  ( Base ‘ 𝐼 )  →  𝑥  ∈  𝑈 ) ) | 
						
							| 47 | 46 | imp | ⊢ ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  →  𝑥  ∈  𝑈 ) | 
						
							| 48 | 47 | adantr | ⊢ ( ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  ∧  ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  →  𝑥  ∈  𝑈 ) | 
						
							| 49 | 43 48 | eqeltrrd | ⊢ ( ( ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  ∧  𝑥  ∈  ( Base ‘ 𝐼 ) )  ∧  ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  →  ( 1r ‘ 𝑅 )  ∈  𝑈 ) | 
						
							| 50 | 49 | rexlimdva2 | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ¬  𝑈  =  {  0  } )  →  ( ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  →  ( 1r ‘ 𝑅 )  ∈  𝑈 ) ) | 
						
							| 51 | 50 | impancom | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  →  ( ¬  𝑈  =  {  0  }  →  ( 1r ‘ 𝑅 )  ∈  𝑈 ) ) | 
						
							| 52 | 9 | adantr | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 ) ) | 
						
							| 53 | 1 3 39 | lidl1el | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  →  ( ( 1r ‘ 𝑅 )  ∈  𝑈  ↔  𝑈  =  𝐵 ) ) | 
						
							| 54 | 52 53 | syl | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ( 1r ‘ 𝑅 )  ∈  𝑈  ↔  𝑈  =  𝐵 ) ) | 
						
							| 55 | 54 | adantr | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  →  ( ( 1r ‘ 𝑅 )  ∈  𝑈  ↔  𝑈  =  𝐵 ) ) | 
						
							| 56 | 51 55 | sylibd | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  →  ( ¬  𝑈  =  {  0  }  →  𝑈  =  𝐵 ) ) | 
						
							| 57 | 56 | orrd | ⊢ ( ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  →  ( 𝑈  =  {  0  }  ∨  𝑈  =  𝐵 ) ) | 
						
							| 58 | 57 | ex | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  →  ( 𝑈  =  {  0  }  ∨  𝑈  =  𝐵 ) ) ) | 
						
							| 59 | 1 2 3 4 | zlidlring | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑈  =  {  0  } )  →  𝐼  ∈  Ring ) | 
						
							| 60 | 7 | simprbi | ⊢ ( 𝐼  ∈  Ring  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 61 | 59 60 | syl | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑈  =  {  0  } )  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 62 | 61 | ex | ⊢ ( 𝑅  ∈  Ring  →  ( 𝑈  =  {  0  }  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 63 | 8 62 | syl | ⊢ ( 𝑅  ∈  Domn  →  ( 𝑈  =  {  0  }  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 64 | 63 | ad2antrr | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( 𝑈  =  {  0  }  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 65 | 9 | anim1i | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng ) ) | 
						
							| 66 | 3 15 | ringideu | ⊢ ( 𝑅  ∈  Ring  →  ∃! 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 67 |  | reurex | ⊢ ( ∃! 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 )  →  ∃ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 68 | 66 67 | syl | ⊢ ( 𝑅  ∈  Ring  →  ∃ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 69 | 68 | adantr | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  →  ∃ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 70 | 69 | ad2antrr | ⊢ ( ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  𝑈  =  𝐵 )  →  ∃ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 71 | 2 3 | ressbas | ⊢ ( 𝑈  ∈  𝐿  →  ( 𝑈  ∩  𝐵 )  =  ( Base ‘ 𝐼 ) ) | 
						
							| 72 | 71 | ad3antlr | ⊢ ( ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  𝑈  =  𝐵 )  →  ( 𝑈  ∩  𝐵 )  =  ( Base ‘ 𝐼 ) ) | 
						
							| 73 |  | ineq1 | ⊢ ( 𝑈  =  𝐵  →  ( 𝑈  ∩  𝐵 )  =  ( 𝐵  ∩  𝐵 ) ) | 
						
							| 74 |  | inidm | ⊢ ( 𝐵  ∩  𝐵 )  =  𝐵 | 
						
							| 75 | 73 74 | eqtrdi | ⊢ ( 𝑈  =  𝐵  →  ( 𝑈  ∩  𝐵 )  =  𝐵 ) | 
						
							| 76 | 75 | adantl | ⊢ ( ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  𝑈  =  𝐵 )  →  ( 𝑈  ∩  𝐵 )  =  𝐵 ) | 
						
							| 77 | 72 76 | eqtr3d | ⊢ ( ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  𝑈  =  𝐵 )  →  ( Base ‘ 𝐼 )  =  𝐵 ) | 
						
							| 78 | 22 | ad3antlr | ⊢ ( ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  𝑈  =  𝐵 )  →  ( ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 79 | 77 78 | raleqbidv | ⊢ ( ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  𝑈  =  𝐵 )  →  ( ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ∀ 𝑦  ∈  𝐵 ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 80 | 77 79 | rexeqbidv | ⊢ ( ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  𝑈  =  𝐵 )  →  ( ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ∃ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ( ( 𝑥 ( .r ‘ 𝑅 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝑅 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 81 | 70 80 | mpbird | ⊢ ( ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  ∧  𝑈  =  𝐵 )  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) | 
						
							| 82 | 81 | ex | ⊢ ( ( ( 𝑅  ∈  Ring  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( 𝑈  =  𝐵  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 83 | 65 82 | syl | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( 𝑈  =  𝐵  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 84 | 64 83 | jaod | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ( 𝑈  =  {  0  }  ∨  𝑈  =  𝐵 )  →  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) ) ) | 
						
							| 85 | 58 84 | impbid | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 )  ↔  ( 𝑈  =  {  0  }  ∨  𝑈  =  𝐵 ) ) ) | 
						
							| 86 | 14 85 | bitrd | ⊢ ( ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  ∧  𝐼  ∈  Rng )  →  ( ( 𝐼  ∈  Rng  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  ↔  ( 𝑈  =  {  0  }  ∨  𝑈  =  𝐵 ) ) ) | 
						
							| 87 | 11 86 | mpdan | ⊢ ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  →  ( ( 𝐼  ∈  Rng  ∧  ∃ 𝑥  ∈  ( Base ‘ 𝐼 ) ∀ 𝑦  ∈  ( Base ‘ 𝐼 ) ( ( 𝑥 ( .r ‘ 𝐼 ) 𝑦 )  =  𝑦  ∧  ( 𝑦 ( .r ‘ 𝐼 ) 𝑥 )  =  𝑦 ) )  ↔  ( 𝑈  =  {  0  }  ∨  𝑈  =  𝐵 ) ) ) | 
						
							| 88 | 7 87 | bitrid | ⊢ ( ( 𝑅  ∈  Domn  ∧  𝑈  ∈  𝐿 )  →  ( 𝐼  ∈  Ring  ↔  ( 𝑈  =  {  0  }  ∨  𝑈  =  𝐵 ) ) ) |