| Step | Hyp | Ref | Expression | 
						
							| 1 |  | breq1 | ⊢ ( 𝑔  =  𝑘  →  ( 𝑔 𝑞 𝑛  ↔  𝑘 𝑞 𝑛 ) ) | 
						
							| 2 | 1 | notbid | ⊢ ( 𝑔  =  𝑘  →  ( ¬  𝑔 𝑞 𝑛  ↔  ¬  𝑘 𝑞 𝑛 ) ) | 
						
							| 3 | 2 | cbvralvw | ⊢ ( ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛  ↔  ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑛 ) | 
						
							| 4 |  | breq2 | ⊢ ( 𝑛  =  𝑚  →  ( 𝑘 𝑞 𝑛  ↔  𝑘 𝑞 𝑚 ) ) | 
						
							| 5 | 4 | notbid | ⊢ ( 𝑛  =  𝑚  →  ( ¬  𝑘 𝑞 𝑛  ↔  ¬  𝑘 𝑞 𝑚 ) ) | 
						
							| 6 | 5 | ralbidv | ⊢ ( 𝑛  =  𝑚  →  ( ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑛  ↔  ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) ) | 
						
							| 7 | 3 6 | bitrid | ⊢ ( 𝑛  =  𝑚  →  ( ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛  ↔  ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) ) | 
						
							| 8 | 7 | cbvriotavw | ⊢ ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 )  =  ( ℩ 𝑚  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) | 
						
							| 9 |  | rneq | ⊢ ( ℎ  =  𝑑  →  ran  ℎ  =  ran  𝑑 ) | 
						
							| 10 | 9 | raleqdv | ⊢ ( ℎ  =  𝑑  →  ( ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣  ↔  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 ) ) | 
						
							| 11 | 10 | rabbidv | ⊢ ( ℎ  =  𝑑  →  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 }  =  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ) | 
						
							| 12 | 11 | raleqdv | ⊢ ( ℎ  =  𝑑  →  ( ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚  ↔  ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) ) | 
						
							| 13 | 11 12 | riotaeqbidv | ⊢ ( ℎ  =  𝑑  →  ( ℩ 𝑚  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 )  =  ( ℩ 𝑚  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) ) | 
						
							| 14 | 8 13 | eqtrid | ⊢ ( ℎ  =  𝑑  →  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 )  =  ( ℩ 𝑚  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) ) | 
						
							| 15 | 14 | cbvmptv | ⊢ ( ℎ  ∈  V  ↦  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 ) )  =  ( 𝑑  ∈  V  ↦  ( ℩ 𝑚  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) ) | 
						
							| 16 |  | recseq | ⊢ ( ( ℎ  ∈  V  ↦  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 ) )  =  ( 𝑑  ∈  V  ↦  ( ℩ 𝑚  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) )  →  recs ( ( ℎ  ∈  V  ↦  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 ) ) )  =  recs ( ( 𝑑  ∈  V  ↦  ( ℩ 𝑚  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) ) ) ) | 
						
							| 17 | 15 16 | ax-mp | ⊢ recs ( ( ℎ  ∈  V  ↦  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 ) ) )  =  recs ( ( 𝑑  ∈  V  ↦  ( ℩ 𝑚  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ∀ 𝑘  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 } ¬  𝑘 𝑞 𝑚 ) ) ) | 
						
							| 18 |  | breq1 | ⊢ ( 𝑞  =  𝑠  →  ( 𝑞 𝑅 𝑣  ↔  𝑠 𝑅 𝑣 ) ) | 
						
							| 19 | 18 | cbvralvw | ⊢ ( ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣  ↔  ∀ 𝑠  ∈  ran  𝑑 𝑠 𝑅 𝑣 ) | 
						
							| 20 |  | breq2 | ⊢ ( 𝑣  =  𝑟  →  ( 𝑠 𝑅 𝑣  ↔  𝑠 𝑅 𝑟 ) ) | 
						
							| 21 | 20 | ralbidv | ⊢ ( 𝑣  =  𝑟  →  ( ∀ 𝑠  ∈  ran  𝑑 𝑠 𝑅 𝑣  ↔  ∀ 𝑠  ∈  ran  𝑑 𝑠 𝑅 𝑟 ) ) | 
						
							| 22 | 19 21 | bitrid | ⊢ ( 𝑣  =  𝑟  →  ( ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣  ↔  ∀ 𝑠  ∈  ran  𝑑 𝑠 𝑅 𝑟 ) ) | 
						
							| 23 | 22 | cbvrabv | ⊢ { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  𝑑 𝑞 𝑅 𝑣 }  =  { 𝑟  ∈  𝐴  ∣  ∀ 𝑠  ∈  ran  𝑑 𝑠 𝑅 𝑟 } | 
						
							| 24 |  | eqid | ⊢ { 𝑟  ∈  𝐴  ∣  ∀ 𝑠  ∈  ( recs ( ( ℎ  ∈  V  ↦  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 ) ) )  “  𝑢 ) 𝑠 𝑅 𝑟 }  =  { 𝑟  ∈  𝐴  ∣  ∀ 𝑠  ∈  ( recs ( ( ℎ  ∈  V  ↦  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 ) ) )  “  𝑢 ) 𝑠 𝑅 𝑟 } | 
						
							| 25 |  | eqid | ⊢ { 𝑟  ∈  𝐴  ∣  ∀ 𝑠  ∈  ( recs ( ( ℎ  ∈  V  ↦  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 ) ) )  “  𝑡 ) 𝑠 𝑅 𝑟 }  =  { 𝑟  ∈  𝐴  ∣  ∀ 𝑠  ∈  ( recs ( ( ℎ  ∈  V  ↦  ( ℩ 𝑛  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ∀ 𝑔  ∈  { 𝑣  ∈  𝐴  ∣  ∀ 𝑞  ∈  ran  ℎ 𝑞 𝑅 𝑣 } ¬  𝑔 𝑞 𝑛 ) ) )  “  𝑡 ) 𝑠 𝑅 𝑟 } | 
						
							| 26 | 17 23 24 25 | zorn2lem7 | ⊢ ( ( 𝐴  ∈  dom  card  ∧  𝑅  Po  𝐴  ∧  ∀ 𝑤 ( ( 𝑤  ⊆  𝐴  ∧  𝑅  Or  𝑤 )  →  ∃ 𝑥  ∈  𝐴 ∀ 𝑧  ∈  𝑤 ( 𝑧 𝑅 𝑥  ∨  𝑧  =  𝑥 ) ) )  →  ∃ 𝑥  ∈  𝐴 ∀ 𝑦  ∈  𝐴 ¬  𝑥 𝑅 𝑦 ) |