| Step | Hyp | Ref | Expression | 
						
							| 1 |  | aomclem6.b | ⊢ 𝐵  =  { 〈 𝑎 ,  𝑏 〉  ∣  ∃ 𝑐  ∈  ( 𝑅1 ‘ ∪  dom  𝑧 ) ( ( 𝑐  ∈  𝑏  ∧  ¬  𝑐  ∈  𝑎 )  ∧  ∀ 𝑑  ∈  ( 𝑅1 ‘ ∪  dom  𝑧 ) ( 𝑑 ( 𝑧 ‘ ∪  dom  𝑧 ) 𝑐  →  ( 𝑑  ∈  𝑎  ↔  𝑑  ∈  𝑏 ) ) ) } | 
						
							| 2 |  | aomclem6.c | ⊢ 𝐶  =  ( 𝑎  ∈  V  ↦  sup ( ( 𝑦 ‘ 𝑎 ) ,  ( 𝑅1 ‘ dom  𝑧 ) ,  𝐵 ) ) | 
						
							| 3 |  | aomclem6.d | ⊢ 𝐷  =  recs ( ( 𝑎  ∈  V  ↦  ( 𝐶 ‘ ( ( 𝑅1 ‘ dom  𝑧 )  ∖  ran  𝑎 ) ) ) ) | 
						
							| 4 |  | aomclem6.e | ⊢ 𝐸  =  { 〈 𝑎 ,  𝑏 〉  ∣  ∩  ( ◡ 𝐷  “  { 𝑎 } )  ∈  ∩  ( ◡ 𝐷  “  { 𝑏 } ) } | 
						
							| 5 |  | aomclem6.f | ⊢ 𝐹  =  { 〈 𝑎 ,  𝑏 〉  ∣  ( ( rank ‘ 𝑎 )  E  ( rank ‘ 𝑏 )  ∨  ( ( rank ‘ 𝑎 )  =  ( rank ‘ 𝑏 )  ∧  𝑎 ( 𝑧 ‘ suc  ( rank ‘ 𝑎 ) ) 𝑏 ) ) } | 
						
							| 6 |  | aomclem6.g | ⊢ 𝐺  =  ( if ( dom  𝑧  =  ∪  dom  𝑧 ,  𝐹 ,  𝐸 )  ∩  ( ( 𝑅1 ‘ dom  𝑧 )  ×  ( 𝑅1 ‘ dom  𝑧 ) ) ) | 
						
							| 7 |  | aomclem6.h | ⊢ 𝐻  =  recs ( ( 𝑧  ∈  V  ↦  𝐺 ) ) | 
						
							| 8 |  | aomclem6.a | ⊢ ( 𝜑  →  𝐴  ∈  On ) | 
						
							| 9 |  | aomclem6.y | ⊢ ( 𝜑  →  ∀ 𝑎  ∈  𝒫  ( 𝑅1 ‘ 𝐴 ) ( 𝑎  ≠  ∅  →  ( 𝑦 ‘ 𝑎 )  ∈  ( ( 𝒫  𝑎  ∩  Fin )  ∖  { ∅ } ) ) ) | 
						
							| 10 | 1 2 3 4 5 6 7 8 9 | aomclem6 | ⊢ ( 𝜑  →  ( 𝐻 ‘ 𝐴 )  We  ( 𝑅1 ‘ 𝐴 ) ) | 
						
							| 11 |  | fvex | ⊢ ( 𝐻 ‘ 𝐴 )  ∈  V | 
						
							| 12 |  | weeq1 | ⊢ ( 𝑏  =  ( 𝐻 ‘ 𝐴 )  →  ( 𝑏  We  ( 𝑅1 ‘ 𝐴 )  ↔  ( 𝐻 ‘ 𝐴 )  We  ( 𝑅1 ‘ 𝐴 ) ) ) | 
						
							| 13 | 11 12 | spcev | ⊢ ( ( 𝐻 ‘ 𝐴 )  We  ( 𝑅1 ‘ 𝐴 )  →  ∃ 𝑏 𝑏  We  ( 𝑅1 ‘ 𝐴 ) ) | 
						
							| 14 | 10 13 | syl | ⊢ ( 𝜑  →  ∃ 𝑏 𝑏  We  ( 𝑅1 ‘ 𝐴 ) ) |