| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							pwexg | 
							⊢ ( 𝐴  ∈  𝑉  →  𝒫  𝐴  ∈  V )  | 
						
						
							| 2 | 
							
								1
							 | 
							adantr | 
							⊢ ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  →  𝒫  𝐴  ∈  V )  | 
						
						
							| 3 | 
							
								2
							 | 
							pwexd | 
							⊢ ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  →  𝒫  𝒫  𝐴  ∈  V )  | 
						
						
							| 4 | 
							
								
							 | 
							ssrab2 | 
							⊢ { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ⊆  𝒫  𝐴  | 
						
						
							| 5 | 
							
								
							 | 
							elpw2g | 
							⊢ ( 𝒫  𝐴  ∈  V  →  ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ∈  𝒫  𝒫  𝐴  ↔  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ⊆  𝒫  𝐴 ) )  | 
						
						
							| 6 | 
							
								2 5
							 | 
							syl | 
							⊢ ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  →  ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ∈  𝒫  𝒫  𝐴  ↔  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ⊆  𝒫  𝐴 ) )  | 
						
						
							| 7 | 
							
								4 6
							 | 
							mpbiri | 
							⊢ ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  →  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ∈  𝒫  𝒫  𝐴 )  | 
						
						
							| 8 | 
							
								7
							 | 
							a1d | 
							⊢ ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  →  ( 𝑏  ∈  ω  →  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ∈  𝒫  𝒫  𝐴 ) )  | 
						
						
							| 9 | 
							
								
							 | 
							isinf | 
							⊢ ( ¬  𝐴  ∈  Fin  →  ∀ 𝑏  ∈  ω ∃ 𝑒 ( 𝑒  ⊆  𝐴  ∧  𝑒  ≈  𝑏 ) )  | 
						
						
							| 10 | 
							
								9
							 | 
							r19.21bi | 
							⊢ ( ( ¬  𝐴  ∈  Fin  ∧  𝑏  ∈  ω )  →  ∃ 𝑒 ( 𝑒  ⊆  𝐴  ∧  𝑒  ≈  𝑏 ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							ad2ant2lr | 
							⊢ ( ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  ∧  ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω ) )  →  ∃ 𝑒 ( 𝑒  ⊆  𝐴  ∧  𝑒  ≈  𝑏 ) )  | 
						
						
							| 12 | 
							
								
							 | 
							velpw | 
							⊢ ( 𝑒  ∈  𝒫  𝐴  ↔  𝑒  ⊆  𝐴 )  | 
						
						
							| 13 | 
							
								12
							 | 
							biimpri | 
							⊢ ( 𝑒  ⊆  𝐴  →  𝑒  ∈  𝒫  𝐴 )  | 
						
						
							| 14 | 
							
								13
							 | 
							anim1i | 
							⊢ ( ( 𝑒  ⊆  𝐴  ∧  𝑒  ≈  𝑏 )  →  ( 𝑒  ∈  𝒫  𝐴  ∧  𝑒  ≈  𝑏 ) )  | 
						
						
							| 15 | 
							
								
							 | 
							breq1 | 
							⊢ ( 𝑑  =  𝑒  →  ( 𝑑  ≈  𝑏  ↔  𝑒  ≈  𝑏 ) )  | 
						
						
							| 16 | 
							
								15
							 | 
							elrab | 
							⊢ ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ↔  ( 𝑒  ∈  𝒫  𝐴  ∧  𝑒  ≈  𝑏 ) )  | 
						
						
							| 17 | 
							
								14 16
							 | 
							sylibr | 
							⊢ ( ( 𝑒  ⊆  𝐴  ∧  𝑒  ≈  𝑏 )  →  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 } )  | 
						
						
							| 18 | 
							
								17
							 | 
							eximi | 
							⊢ ( ∃ 𝑒 ( 𝑒  ⊆  𝐴  ∧  𝑒  ≈  𝑏 )  →  ∃ 𝑒 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 } )  | 
						
						
							| 19 | 
							
								11 18
							 | 
							syl | 
							⊢ ( ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  ∧  ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω ) )  →  ∃ 𝑒 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 } )  | 
						
						
							| 20 | 
							
								
							 | 
							eleq2 | 
							⊢ ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  =  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  →  ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ↔  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 } ) )  | 
						
						
							| 21 | 
							
								20
							 | 
							biimpcd | 
							⊢ ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  →  ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  =  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  →  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 } ) )  | 
						
						
							| 22 | 
							
								21
							 | 
							adantl | 
							⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  ∧  ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω ) )  ∧  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 } )  →  ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  =  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  →  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 } ) )  | 
						
						
							| 23 | 
							
								16
							 | 
							simprbi | 
							⊢ ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  →  𝑒  ≈  𝑏 )  | 
						
						
							| 24 | 
							
								
							 | 
							breq1 | 
							⊢ ( 𝑑  =  𝑒  →  ( 𝑑  ≈  𝑐  ↔  𝑒  ≈  𝑐 ) )  | 
						
						
							| 25 | 
							
								24
							 | 
							elrab | 
							⊢ ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  ↔  ( 𝑒  ∈  𝒫  𝐴  ∧  𝑒  ≈  𝑐 ) )  | 
						
						
							| 26 | 
							
								25
							 | 
							simprbi | 
							⊢ ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  →  𝑒  ≈  𝑐 )  | 
						
						
							| 27 | 
							
								
							 | 
							ensym | 
							⊢ ( 𝑒  ≈  𝑏  →  𝑏  ≈  𝑒 )  | 
						
						
							| 28 | 
							
								
							 | 
							entr | 
							⊢ ( ( 𝑏  ≈  𝑒  ∧  𝑒  ≈  𝑐 )  →  𝑏  ≈  𝑐 )  | 
						
						
							| 29 | 
							
								27 28
							 | 
							sylan | 
							⊢ ( ( 𝑒  ≈  𝑏  ∧  𝑒  ≈  𝑐 )  →  𝑏  ≈  𝑐 )  | 
						
						
							| 30 | 
							
								23 26 29
							 | 
							syl2an | 
							⊢ ( ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  ∧  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 } )  →  𝑏  ≈  𝑐 )  | 
						
						
							| 31 | 
							
								30
							 | 
							ex | 
							⊢ ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  →  ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  →  𝑏  ≈  𝑐 ) )  | 
						
						
							| 32 | 
							
								31
							 | 
							adantl | 
							⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  ∧  ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω ) )  ∧  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 } )  →  ( 𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  →  𝑏  ≈  𝑐 ) )  | 
						
						
							| 33 | 
							
								
							 | 
							nneneq | 
							⊢ ( ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω )  →  ( 𝑏  ≈  𝑐  ↔  𝑏  =  𝑐 ) )  | 
						
						
							| 34 | 
							
								33
							 | 
							biimpd | 
							⊢ ( ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω )  →  ( 𝑏  ≈  𝑐  →  𝑏  =  𝑐 ) )  | 
						
						
							| 35 | 
							
								34
							 | 
							ad2antlr | 
							⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  ∧  ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω ) )  ∧  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 } )  →  ( 𝑏  ≈  𝑐  →  𝑏  =  𝑐 ) )  | 
						
						
							| 36 | 
							
								22 32 35
							 | 
							3syld | 
							⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  ∧  ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω ) )  ∧  𝑒  ∈  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 } )  →  ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  =  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  →  𝑏  =  𝑐 ) )  | 
						
						
							| 37 | 
							
								19 36
							 | 
							exlimddv | 
							⊢ ( ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  ∧  ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω ) )  →  ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  =  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  →  𝑏  =  𝑐 ) )  | 
						
						
							| 38 | 
							
								
							 | 
							breq2 | 
							⊢ ( 𝑏  =  𝑐  →  ( 𝑑  ≈  𝑏  ↔  𝑑  ≈  𝑐 ) )  | 
						
						
							| 39 | 
							
								38
							 | 
							rabbidv | 
							⊢ ( 𝑏  =  𝑐  →  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  =  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 } )  | 
						
						
							| 40 | 
							
								37 39
							 | 
							impbid1 | 
							⊢ ( ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  ∧  ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω ) )  →  ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  =  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  ↔  𝑏  =  𝑐 ) )  | 
						
						
							| 41 | 
							
								40
							 | 
							ex | 
							⊢ ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  →  ( ( 𝑏  ∈  ω  ∧  𝑐  ∈  ω )  →  ( { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑏 }  =  { 𝑑  ∈  𝒫  𝐴  ∣  𝑑  ≈  𝑐 }  ↔  𝑏  =  𝑐 ) ) )  | 
						
						
							| 42 | 
							
								8 41
							 | 
							dom2d | 
							⊢ ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  →  ( 𝒫  𝒫  𝐴  ∈  V  →  ω  ≼  𝒫  𝒫  𝐴 ) )  | 
						
						
							| 43 | 
							
								3 42
							 | 
							mpd | 
							⊢ ( ( 𝐴  ∈  𝑉  ∧  ¬  𝐴  ∈  Fin )  →  ω  ≼  𝒫  𝒫  𝐴 )  |