| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isldsys.l | ⊢ 𝐿  =  { 𝑠  ∈  𝒫  𝒫  𝑂  ∣  ( ∅  ∈  𝑠  ∧  ∀ 𝑥  ∈  𝑠 ( 𝑂  ∖  𝑥 )  ∈  𝑠  ∧  ∀ 𝑥  ∈  𝒫  𝑠 ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  𝑠 ) ) } | 
						
							| 2 |  | ldsysgenld.1 | ⊢ ( 𝜑  →  𝑂  ∈  𝑉 ) | 
						
							| 3 |  | ldsysgenld.2 | ⊢ ( 𝜑  →  𝐴  ⊆  𝒫  𝑂 ) | 
						
							| 4 |  | pwsiga | ⊢ ( 𝑂  ∈  𝑉  →  𝒫  𝑂  ∈  ( sigAlgebra ‘ 𝑂 ) ) | 
						
							| 5 | 2 4 | syl | ⊢ ( 𝜑  →  𝒫  𝑂  ∈  ( sigAlgebra ‘ 𝑂 ) ) | 
						
							| 6 | 1 | sigaldsys | ⊢ ( sigAlgebra ‘ 𝑂 )  ⊆  𝐿 | 
						
							| 7 | 6 5 | sselid | ⊢ ( 𝜑  →  𝒫  𝑂  ∈  𝐿 ) | 
						
							| 8 |  | sseq2 | ⊢ ( 𝑡  =  𝒫  𝑂  →  ( 𝐴  ⊆  𝑡  ↔  𝐴  ⊆  𝒫  𝑂 ) ) | 
						
							| 9 | 8 | elrab | ⊢ ( 𝒫  𝑂  ∈  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ↔  ( 𝒫  𝑂  ∈  𝐿  ∧  𝐴  ⊆  𝒫  𝑂 ) ) | 
						
							| 10 | 7 3 9 | sylanbrc | ⊢ ( 𝜑  →  𝒫  𝑂  ∈  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 11 |  | intss1 | ⊢ ( 𝒫  𝑂  ∈  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  →  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ⊆  𝒫  𝑂 ) | 
						
							| 12 | 10 11 | syl | ⊢ ( 𝜑  →  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ⊆  𝒫  𝑂 ) | 
						
							| 13 | 5 12 | sselpwd | ⊢ ( 𝜑  →  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∈  𝒫  𝒫  𝑂 ) | 
						
							| 14 | 1 | isldsys | ⊢ ( 𝑡  ∈  𝐿  ↔  ( 𝑡  ∈  𝒫  𝒫  𝑂  ∧  ( ∅  ∈  𝑡  ∧  ∀ 𝑥  ∈  𝑡 ( 𝑂  ∖  𝑥 )  ∈  𝑡  ∧  ∀ 𝑥  ∈  𝒫  𝑡 ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  𝑡 ) ) ) ) | 
						
							| 15 | 14 | simprbi | ⊢ ( 𝑡  ∈  𝐿  →  ( ∅  ∈  𝑡  ∧  ∀ 𝑥  ∈  𝑡 ( 𝑂  ∖  𝑥 )  ∈  𝑡  ∧  ∀ 𝑥  ∈  𝒫  𝑡 ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  𝑡 ) ) ) | 
						
							| 16 | 15 | simp1d | ⊢ ( 𝑡  ∈  𝐿  →  ∅  ∈  𝑡 ) | 
						
							| 17 | 16 | adantl | ⊢ ( ( 𝜑  ∧  𝑡  ∈  𝐿 )  →  ∅  ∈  𝑡 ) | 
						
							| 18 | 17 | a1d | ⊢ ( ( 𝜑  ∧  𝑡  ∈  𝐿 )  →  ( 𝐴  ⊆  𝑡  →  ∅  ∈  𝑡 ) ) | 
						
							| 19 | 18 | ralrimiva | ⊢ ( 𝜑  →  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  ∅  ∈  𝑡 ) ) | 
						
							| 20 |  | 0ex | ⊢ ∅  ∈  V | 
						
							| 21 | 20 | elintrab | ⊢ ( ∅  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ↔  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  ∅  ∈  𝑡 ) ) | 
						
							| 22 | 19 21 | sylibr | ⊢ ( 𝜑  →  ∅  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 23 |  | nfv | ⊢ Ⅎ 𝑡 𝜑 | 
						
							| 24 |  | nfcv | ⊢ Ⅎ 𝑡 𝑥 | 
						
							| 25 |  | nfrab1 | ⊢ Ⅎ 𝑡 { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } | 
						
							| 26 | 25 | nfint | ⊢ Ⅎ 𝑡 ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } | 
						
							| 27 | 24 26 | nfel | ⊢ Ⅎ 𝑡 𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } | 
						
							| 28 | 23 27 | nfan | ⊢ Ⅎ 𝑡 ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 29 |  | simplr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  𝑡  ∈  𝐿 ) | 
						
							| 30 |  | vex | ⊢ 𝑥  ∈  V | 
						
							| 31 | 30 | elintrab | ⊢ ( 𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ↔  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  𝑥  ∈  𝑡 ) ) | 
						
							| 32 | 31 | biimpi | ⊢ ( 𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  →  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  𝑥  ∈  𝑡 ) ) | 
						
							| 33 | 32 | adantl | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  𝑥  ∈  𝑡 ) ) | 
						
							| 34 | 33 | r19.21bi | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  𝑡  ∈  𝐿 )  →  ( 𝐴  ⊆  𝑡  →  𝑥  ∈  𝑡 ) ) | 
						
							| 35 | 34 | imp | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  𝑥  ∈  𝑡 ) | 
						
							| 36 | 15 | simp2d | ⊢ ( 𝑡  ∈  𝐿  →  ∀ 𝑥  ∈  𝑡 ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) | 
						
							| 37 | 36 | r19.21bi | ⊢ ( ( 𝑡  ∈  𝐿  ∧  𝑥  ∈  𝑡 )  →  ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) | 
						
							| 38 | 29 35 37 | syl2anc | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) | 
						
							| 39 | 38 | ex | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  𝑡  ∈  𝐿 )  →  ( 𝐴  ⊆  𝑡  →  ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) ) | 
						
							| 40 | 39 | ex | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  ( 𝑡  ∈  𝐿  →  ( 𝐴  ⊆  𝑡  →  ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) ) ) | 
						
							| 41 | 28 40 | ralrimi | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) ) | 
						
							| 42 |  | difexg | ⊢ ( 𝑂  ∈  𝑉  →  ( 𝑂  ∖  𝑥 )  ∈  V ) | 
						
							| 43 |  | elintrabg | ⊢ ( ( 𝑂  ∖  𝑥 )  ∈  V  →  ( ( 𝑂  ∖  𝑥 )  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ↔  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) ) ) | 
						
							| 44 | 2 42 43 | 3syl | ⊢ ( 𝜑  →  ( ( 𝑂  ∖  𝑥 )  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ↔  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) ) ) | 
						
							| 45 | 44 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  ( ( 𝑂  ∖  𝑥 )  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ↔  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  ( 𝑂  ∖  𝑥 )  ∈  𝑡 ) ) ) | 
						
							| 46 | 41 45 | mpbird | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  ( 𝑂  ∖  𝑥 )  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 47 | 46 | ralrimiva | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ( 𝑂  ∖  𝑥 )  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 48 | 26 | nfpw | ⊢ Ⅎ 𝑡 𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } | 
						
							| 49 | 24 48 | nfel | ⊢ Ⅎ 𝑡 𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } | 
						
							| 50 | 23 49 | nfan | ⊢ Ⅎ 𝑡 ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 51 |  | nfv | ⊢ Ⅎ 𝑡 ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) | 
						
							| 52 | 50 51 | nfan | ⊢ Ⅎ 𝑡 ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) ) | 
						
							| 53 |  | simplr | ⊢ ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  𝑡  ∈  𝐿 ) | 
						
							| 54 |  | simpr | ⊢ ( ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  ∧  𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 55 |  | simpllr | ⊢ ( ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  ∧  𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  𝑡  ∈  𝐿 ) | 
						
							| 56 |  | simplr | ⊢ ( ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  ∧  𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  𝐴  ⊆  𝑡 ) | 
						
							| 57 |  | vex | ⊢ 𝑢  ∈  V | 
						
							| 58 | 57 | elintrab | ⊢ ( 𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ↔  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  𝑢  ∈  𝑡 ) ) | 
						
							| 59 | 58 | biimpi | ⊢ ( 𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  →  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  𝑢  ∈  𝑡 ) ) | 
						
							| 60 | 59 | r19.21bi | ⊢ ( ( 𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∧  𝑡  ∈  𝐿 )  →  ( 𝐴  ⊆  𝑡  →  𝑢  ∈  𝑡 ) ) | 
						
							| 61 | 60 | imp | ⊢ ( ( ( 𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  𝑢  ∈  𝑡 ) | 
						
							| 62 | 54 55 56 61 | syl21anc | ⊢ ( ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  ∧  𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  𝑢  ∈  𝑡 ) | 
						
							| 63 | 62 | ex | ⊢ ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  ( 𝑢  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  →  𝑢  ∈  𝑡 ) ) | 
						
							| 64 | 63 | ssrdv | ⊢ ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ⊆  𝑡 ) | 
						
							| 65 | 64 | sspwd | ⊢ ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ⊆  𝒫  𝑡 ) | 
						
							| 66 |  | simp-4r | ⊢ ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 67 | 65 66 | sseldd | ⊢ ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  𝑥  ∈  𝒫  𝑡 ) | 
						
							| 68 |  | simpllr | ⊢ ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) ) | 
						
							| 69 | 15 | simp3d | ⊢ ( 𝑡  ∈  𝐿  →  ∀ 𝑥  ∈  𝒫  𝑡 ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  𝑡 ) ) | 
						
							| 70 | 69 | r19.21bi | ⊢ ( ( 𝑡  ∈  𝐿  ∧  𝑥  ∈  𝒫  𝑡 )  →  ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  𝑡 ) ) | 
						
							| 71 | 70 | imp | ⊢ ( ( ( 𝑡  ∈  𝐿  ∧  𝑥  ∈  𝒫  𝑡 )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  →  ∪  𝑥  ∈  𝑡 ) | 
						
							| 72 | 53 67 68 71 | syl21anc | ⊢ ( ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  ∧  𝐴  ⊆  𝑡 )  →  ∪  𝑥  ∈  𝑡 ) | 
						
							| 73 | 72 | ex | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  ∧  𝑡  ∈  𝐿 )  →  ( 𝐴  ⊆  𝑡  →  ∪  𝑥  ∈  𝑡 ) ) | 
						
							| 74 | 73 | ex | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  →  ( 𝑡  ∈  𝐿  →  ( 𝐴  ⊆  𝑡  →  ∪  𝑥  ∈  𝑡 ) ) ) | 
						
							| 75 | 52 74 | ralrimi | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  →  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  ∪  𝑥  ∈  𝑡 ) ) | 
						
							| 76 |  | vuniex | ⊢ ∪  𝑥  ∈  V | 
						
							| 77 | 76 | elintrab | ⊢ ( ∪  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ↔  ∀ 𝑡  ∈  𝐿 ( 𝐴  ⊆  𝑡  →  ∪  𝑥  ∈  𝑡 ) ) | 
						
							| 78 | 75 77 | sylibr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  ∧  ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 ) )  →  ∪  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) | 
						
							| 79 | 78 | ex | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } )  →  ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) ) | 
						
							| 80 | 79 | ralrimiva | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) ) | 
						
							| 81 | 22 47 80 | 3jca | ⊢ ( 𝜑  →  ( ∅  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∧  ∀ 𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ( 𝑂  ∖  𝑥 )  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∧  ∀ 𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) ) ) | 
						
							| 82 | 13 81 | jca | ⊢ ( 𝜑  →  ( ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∈  𝒫  𝒫  𝑂  ∧  ( ∅  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∧  ∀ 𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ( 𝑂  ∖  𝑥 )  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∧  ∀ 𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) ) ) ) | 
						
							| 83 | 1 | isldsys | ⊢ ( ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∈  𝐿  ↔  ( ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∈  𝒫  𝒫  𝑂  ∧  ( ∅  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∧  ∀ 𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ( 𝑂  ∖  𝑥 )  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∧  ∀ 𝑥  ∈  𝒫  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ( ( 𝑥  ≼  ω  ∧  Disj  𝑦  ∈  𝑥 𝑦 )  →  ∪  𝑥  ∈  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 } ) ) ) ) | 
						
							| 84 | 82 83 | sylibr | ⊢ ( 𝜑  →  ∩  { 𝑡  ∈  𝐿  ∣  𝐴  ⊆  𝑡 }  ∈  𝐿 ) |