| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elfuns.1 | ⊢ 𝐹  ∈  V | 
						
							| 2 |  | elrel | ⊢ ( ( Rel  𝐹  ∧  𝑝  ∈  𝐹 )  →  ∃ 𝑥 ∃ 𝑦 𝑝  =  〈 𝑥 ,  𝑦 〉 ) | 
						
							| 3 | 2 | ex | ⊢ ( Rel  𝐹  →  ( 𝑝  ∈  𝐹  →  ∃ 𝑥 ∃ 𝑦 𝑝  =  〈 𝑥 ,  𝑦 〉 ) ) | 
						
							| 4 |  | elrel | ⊢ ( ( Rel  𝐹  ∧  𝑞  ∈  𝐹 )  →  ∃ 𝑎 ∃ 𝑧 𝑞  =  〈 𝑎 ,  𝑧 〉 ) | 
						
							| 5 | 4 | ex | ⊢ ( Rel  𝐹  →  ( 𝑞  ∈  𝐹  →  ∃ 𝑎 ∃ 𝑧 𝑞  =  〈 𝑎 ,  𝑧 〉 ) ) | 
						
							| 6 | 3 5 | anim12d | ⊢ ( Rel  𝐹  →  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  →  ( ∃ 𝑥 ∃ 𝑦 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ∃ 𝑎 ∃ 𝑧 𝑞  =  〈 𝑎 ,  𝑧 〉 ) ) ) | 
						
							| 7 | 6 | adantrd | ⊢ ( Rel  𝐹  →  ( ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 )  →  ( ∃ 𝑥 ∃ 𝑦 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ∃ 𝑎 ∃ 𝑧 𝑞  =  〈 𝑎 ,  𝑧 〉 ) ) ) | 
						
							| 8 | 7 | pm4.71rd | ⊢ ( Rel  𝐹  →  ( ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 )  ↔  ( ( ∃ 𝑥 ∃ 𝑦 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ∃ 𝑎 ∃ 𝑧 𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) ) | 
						
							| 9 |  | 19.41vvvv | ⊢ ( ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ( ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 10 |  | ee4anv | ⊢ ( ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ↔  ( ∃ 𝑥 ∃ 𝑦 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ∃ 𝑎 ∃ 𝑧 𝑞  =  〈 𝑎 ,  𝑧 〉 ) ) | 
						
							| 11 | 10 | anbi1i | ⊢ ( ( ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ( ( ∃ 𝑥 ∃ 𝑦 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ∃ 𝑎 ∃ 𝑧 𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 12 | 9 11 | bitr2i | ⊢ ( ( ( ∃ 𝑥 ∃ 𝑦 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ∃ 𝑎 ∃ 𝑧 𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 13 | 8 12 | bitrdi | ⊢ ( Rel  𝐹  →  ( ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 )  ↔  ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) ) | 
						
							| 14 | 13 | 2exbidv | ⊢ ( Rel  𝐹  →  ( ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 )  ↔  ∃ 𝑝 ∃ 𝑞 ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) ) | 
						
							| 15 |  | excom13 | ⊢ ( ∃ 𝑝 ∃ 𝑞 ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑥 ∃ 𝑞 ∃ 𝑝 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 16 |  | excom13 | ⊢ ( ∃ 𝑞 ∃ 𝑝 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑦 ∃ 𝑝 ∃ 𝑞 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 17 |  | exrot4 | ⊢ ( ∃ 𝑝 ∃ 𝑞 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑎 ∃ 𝑧 ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 18 |  | excom | ⊢ ( ∃ 𝑎 ∃ 𝑧 ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑧 ∃ 𝑎 ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 19 |  | df-3an | ⊢ ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 20 | 19 | 2exbii | ⊢ ( ∃ 𝑝 ∃ 𝑞 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 21 |  | opex | ⊢ 〈 𝑥 ,  𝑦 〉  ∈  V | 
						
							| 22 |  | opex | ⊢ 〈 𝑎 ,  𝑧 〉  ∈  V | 
						
							| 23 |  | eleq1 | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( 𝑝  ∈  𝐹  ↔  〈 𝑥 ,  𝑦 〉  ∈  𝐹 ) ) | 
						
							| 24 | 23 | anbi1d | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ↔  ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  𝑞  ∈  𝐹 ) ) ) | 
						
							| 25 |  | breq2 | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( 𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝  ↔  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉 ) ) | 
						
							| 26 | 24 25 | anbi12d | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 )  ↔  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉 ) ) ) | 
						
							| 27 |  | eleq1 | ⊢ ( 𝑞  =  〈 𝑎 ,  𝑧 〉  →  ( 𝑞  ∈  𝐹  ↔  〈 𝑎 ,  𝑧 〉  ∈  𝐹 ) ) | 
						
							| 28 | 27 | anbi2d | ⊢ ( 𝑞  =  〈 𝑎 ,  𝑧 〉  →  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ↔  ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 ) ) ) | 
						
							| 29 |  | breq1 | ⊢ ( 𝑞  =  〈 𝑎 ,  𝑧 〉  →  ( 𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉  ↔  〈 𝑎 ,  𝑧 〉 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉 ) ) | 
						
							| 30 |  | vex | ⊢ 𝑥  ∈  V | 
						
							| 31 |  | vex | ⊢ 𝑦  ∈  V | 
						
							| 32 | 22 30 31 | brtxp | ⊢ ( 〈 𝑎 ,  𝑧 〉 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉  ↔  ( 〈 𝑎 ,  𝑧 〉 1st  𝑥  ∧  〈 𝑎 ,  𝑧 〉 ( ( V  ∖   I  )  ∘  2nd  ) 𝑦 ) ) | 
						
							| 33 |  | vex | ⊢ 𝑎  ∈  V | 
						
							| 34 |  | vex | ⊢ 𝑧  ∈  V | 
						
							| 35 | 33 34 | br1steq | ⊢ ( 〈 𝑎 ,  𝑧 〉 1st  𝑥  ↔  𝑥  =  𝑎 ) | 
						
							| 36 |  | equcom | ⊢ ( 𝑥  =  𝑎  ↔  𝑎  =  𝑥 ) | 
						
							| 37 | 35 36 | bitri | ⊢ ( 〈 𝑎 ,  𝑧 〉 1st  𝑥  ↔  𝑎  =  𝑥 ) | 
						
							| 38 | 22 31 | brco | ⊢ ( 〈 𝑎 ,  𝑧 〉 ( ( V  ∖   I  )  ∘  2nd  ) 𝑦  ↔  ∃ 𝑥 ( 〈 𝑎 ,  𝑧 〉 2nd  𝑥  ∧  𝑥 ( V  ∖   I  ) 𝑦 ) ) | 
						
							| 39 | 33 34 | br2ndeq | ⊢ ( 〈 𝑎 ,  𝑧 〉 2nd  𝑥  ↔  𝑥  =  𝑧 ) | 
						
							| 40 | 39 | anbi1i | ⊢ ( ( 〈 𝑎 ,  𝑧 〉 2nd  𝑥  ∧  𝑥 ( V  ∖   I  ) 𝑦 )  ↔  ( 𝑥  =  𝑧  ∧  𝑥 ( V  ∖   I  ) 𝑦 ) ) | 
						
							| 41 | 40 | exbii | ⊢ ( ∃ 𝑥 ( 〈 𝑎 ,  𝑧 〉 2nd  𝑥  ∧  𝑥 ( V  ∖   I  ) 𝑦 )  ↔  ∃ 𝑥 ( 𝑥  =  𝑧  ∧  𝑥 ( V  ∖   I  ) 𝑦 ) ) | 
						
							| 42 |  | breq1 | ⊢ ( 𝑥  =  𝑧  →  ( 𝑥 ( V  ∖   I  ) 𝑦  ↔  𝑧 ( V  ∖   I  ) 𝑦 ) ) | 
						
							| 43 |  | brv | ⊢ 𝑧 V 𝑦 | 
						
							| 44 |  | brdif | ⊢ ( 𝑧 ( V  ∖   I  ) 𝑦  ↔  ( 𝑧 V 𝑦  ∧  ¬  𝑧  I  𝑦 ) ) | 
						
							| 45 | 43 44 | mpbiran | ⊢ ( 𝑧 ( V  ∖   I  ) 𝑦  ↔  ¬  𝑧  I  𝑦 ) | 
						
							| 46 | 31 | ideq | ⊢ ( 𝑧  I  𝑦  ↔  𝑧  =  𝑦 ) | 
						
							| 47 |  | equcom | ⊢ ( 𝑧  =  𝑦  ↔  𝑦  =  𝑧 ) | 
						
							| 48 | 46 47 | bitri | ⊢ ( 𝑧  I  𝑦  ↔  𝑦  =  𝑧 ) | 
						
							| 49 | 48 | notbii | ⊢ ( ¬  𝑧  I  𝑦  ↔  ¬  𝑦  =  𝑧 ) | 
						
							| 50 | 45 49 | bitri | ⊢ ( 𝑧 ( V  ∖   I  ) 𝑦  ↔  ¬  𝑦  =  𝑧 ) | 
						
							| 51 | 42 50 | bitrdi | ⊢ ( 𝑥  =  𝑧  →  ( 𝑥 ( V  ∖   I  ) 𝑦  ↔  ¬  𝑦  =  𝑧 ) ) | 
						
							| 52 | 51 | equsexvw | ⊢ ( ∃ 𝑥 ( 𝑥  =  𝑧  ∧  𝑥 ( V  ∖   I  ) 𝑦 )  ↔  ¬  𝑦  =  𝑧 ) | 
						
							| 53 | 38 41 52 | 3bitri | ⊢ ( 〈 𝑎 ,  𝑧 〉 ( ( V  ∖   I  )  ∘  2nd  ) 𝑦  ↔  ¬  𝑦  =  𝑧 ) | 
						
							| 54 | 37 53 | anbi12i | ⊢ ( ( 〈 𝑎 ,  𝑧 〉 1st  𝑥  ∧  〈 𝑎 ,  𝑧 〉 ( ( V  ∖   I  )  ∘  2nd  ) 𝑦 )  ↔  ( 𝑎  =  𝑥  ∧  ¬  𝑦  =  𝑧 ) ) | 
						
							| 55 | 32 54 | bitri | ⊢ ( 〈 𝑎 ,  𝑧 〉 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉  ↔  ( 𝑎  =  𝑥  ∧  ¬  𝑦  =  𝑧 ) ) | 
						
							| 56 | 29 55 | bitrdi | ⊢ ( 𝑞  =  〈 𝑎 ,  𝑧 〉  →  ( 𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉  ↔  ( 𝑎  =  𝑥  ∧  ¬  𝑦  =  𝑧 ) ) ) | 
						
							| 57 | 28 56 | anbi12d | ⊢ ( 𝑞  =  〈 𝑎 ,  𝑧 〉  →  ( ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉 )  ↔  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ( 𝑎  =  𝑥  ∧  ¬  𝑦  =  𝑧 ) ) ) ) | 
						
							| 58 |  | an12 | ⊢ ( ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ( 𝑎  =  𝑥  ∧  ¬  𝑦  =  𝑧 ) )  ↔  ( 𝑎  =  𝑥  ∧  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) ) | 
						
							| 59 | 57 58 | bitrdi | ⊢ ( 𝑞  =  〈 𝑎 ,  𝑧 〉  →  ( ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 〈 𝑥 ,  𝑦 〉 )  ↔  ( 𝑎  =  𝑥  ∧  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) ) ) | 
						
							| 60 | 21 22 26 59 | ceqsex2v | ⊢ ( ∃ 𝑝 ∃ 𝑞 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ( 𝑎  =  𝑥  ∧  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) ) | 
						
							| 61 | 20 60 | bitr3i | ⊢ ( ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ( 𝑎  =  𝑥  ∧  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) ) | 
						
							| 62 | 61 | exbii | ⊢ ( ∃ 𝑎 ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑎 ( 𝑎  =  𝑥  ∧  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) ) | 
						
							| 63 |  | opeq1 | ⊢ ( 𝑎  =  𝑥  →  〈 𝑎 ,  𝑧 〉  =  〈 𝑥 ,  𝑧 〉 ) | 
						
							| 64 | 63 | eleq1d | ⊢ ( 𝑎  =  𝑥  →  ( 〈 𝑎 ,  𝑧 〉  ∈  𝐹  ↔  〈 𝑥 ,  𝑧 〉  ∈  𝐹 ) ) | 
						
							| 65 | 64 | anbi2d | ⊢ ( 𝑎  =  𝑥  →  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ↔  ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 ) ) ) | 
						
							| 66 | 65 | anbi1d | ⊢ ( 𝑎  =  𝑥  →  ( ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 )  ↔  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) ) | 
						
							| 67 | 66 | equsexvw | ⊢ ( ∃ 𝑎 ( 𝑎  =  𝑥  ∧  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑎 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) )  ↔  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) | 
						
							| 68 | 62 67 | bitri | ⊢ ( ∃ 𝑎 ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) | 
						
							| 69 | 68 | exbii | ⊢ ( ∃ 𝑧 ∃ 𝑎 ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 ) ) | 
						
							| 70 |  | exanali | ⊢ ( ∃ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  ∧  ¬  𝑦  =  𝑧 )  ↔  ¬  ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 71 | 69 70 | bitri | ⊢ ( ∃ 𝑧 ∃ 𝑎 ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ¬  ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 72 | 17 18 71 | 3bitri | ⊢ ( ∃ 𝑝 ∃ 𝑞 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ¬  ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 73 | 72 | exbii | ⊢ ( ∃ 𝑦 ∃ 𝑝 ∃ 𝑞 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑦 ¬  ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 74 |  | exnal | ⊢ ( ∃ 𝑦 ¬  ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 )  ↔  ¬  ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 75 | 16 73 74 | 3bitri | ⊢ ( ∃ 𝑞 ∃ 𝑝 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ¬  ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 76 | 75 | exbii | ⊢ ( ∃ 𝑥 ∃ 𝑞 ∃ 𝑝 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ∃ 𝑥 ¬  ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 77 |  | exnal | ⊢ ( ∃ 𝑥 ¬  ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 )  ↔  ¬  ∀ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 78 | 15 76 77 | 3bitri | ⊢ ( ∃ 𝑝 ∃ 𝑞 ∃ 𝑥 ∃ 𝑦 ∃ 𝑎 ∃ 𝑧 ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  𝑞  =  〈 𝑎 ,  𝑧 〉 )  ∧  ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) )  ↔  ¬  ∀ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) | 
						
							| 79 | 14 78 | bitrdi | ⊢ ( Rel  𝐹  →  ( ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 )  ↔  ¬  ∀ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) ) | 
						
							| 80 | 79 | con2bid | ⊢ ( Rel  𝐹  →  ( ∀ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 )  ↔  ¬  ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 81 | 80 | pm5.32i | ⊢ ( ( Rel  𝐹  ∧  ∀ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) )  ↔  ( Rel  𝐹  ∧  ¬  ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 82 |  | dffun4 | ⊢ ( Fun  𝐹  ↔  ( Rel  𝐹  ∧  ∀ 𝑥 ∀ 𝑦 ∀ 𝑧 ( ( 〈 𝑥 ,  𝑦 〉  ∈  𝐹  ∧  〈 𝑥 ,  𝑧 〉  ∈  𝐹 )  →  𝑦  =  𝑧 ) ) ) | 
						
							| 83 |  | df-funs | ⊢  Funs   =  ( 𝒫  ( V  ×  V )  ∖   Fix  (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) ) ) | 
						
							| 84 | 83 | eleq2i | ⊢ ( 𝐹  ∈   Funs   ↔  𝐹  ∈  ( 𝒫  ( V  ×  V )  ∖   Fix  (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) ) ) ) | 
						
							| 85 |  | eldif | ⊢ ( 𝐹  ∈  ( 𝒫  ( V  ×  V )  ∖   Fix  (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) ) )  ↔  ( 𝐹  ∈  𝒫  ( V  ×  V )  ∧  ¬  𝐹  ∈   Fix  (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) ) ) ) | 
						
							| 86 | 1 | elpw | ⊢ ( 𝐹  ∈  𝒫  ( V  ×  V )  ↔  𝐹  ⊆  ( V  ×  V ) ) | 
						
							| 87 |  | df-rel | ⊢ ( Rel  𝐹  ↔  𝐹  ⊆  ( V  ×  V ) ) | 
						
							| 88 | 86 87 | bitr4i | ⊢ ( 𝐹  ∈  𝒫  ( V  ×  V )  ↔  Rel  𝐹 ) | 
						
							| 89 | 1 | elfix | ⊢ ( 𝐹  ∈   Fix  (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) )  ↔  𝐹 (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) ) 𝐹 ) | 
						
							| 90 | 1 1 | coep | ⊢ ( 𝐹 (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) ) 𝐹  ↔  ∃ 𝑝  ∈  𝐹 𝐹 ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) 𝑝 ) | 
						
							| 91 |  | vex | ⊢ 𝑝  ∈  V | 
						
							| 92 | 1 91 | coepr | ⊢ ( 𝐹 ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) 𝑝  ↔  ∃ 𝑞  ∈  𝐹 𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) | 
						
							| 93 | 92 | rexbii | ⊢ ( ∃ 𝑝  ∈  𝐹 𝐹 ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) 𝑝  ↔  ∃ 𝑝  ∈  𝐹 ∃ 𝑞  ∈  𝐹 𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) | 
						
							| 94 | 90 93 | bitri | ⊢ ( 𝐹 (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) ) 𝐹  ↔  ∃ 𝑝  ∈  𝐹 ∃ 𝑞  ∈  𝐹 𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) | 
						
							| 95 |  | r2ex | ⊢ ( ∃ 𝑝  ∈  𝐹 ∃ 𝑞  ∈  𝐹 𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝  ↔  ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) | 
						
							| 96 | 89 94 95 | 3bitri | ⊢ ( 𝐹  ∈   Fix  (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) )  ↔  ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) | 
						
							| 97 | 96 | notbii | ⊢ ( ¬  𝐹  ∈   Fix  (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) )  ↔  ¬  ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) | 
						
							| 98 | 88 97 | anbi12i | ⊢ ( ( 𝐹  ∈  𝒫  ( V  ×  V )  ∧  ¬  𝐹  ∈   Fix  (  E   ∘  ( ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) )  ∘  ◡  E  ) ) )  ↔  ( Rel  𝐹  ∧  ¬  ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 99 | 84 85 98 | 3bitri | ⊢ ( 𝐹  ∈   Funs   ↔  ( Rel  𝐹  ∧  ¬  ∃ 𝑝 ∃ 𝑞 ( ( 𝑝  ∈  𝐹  ∧  𝑞  ∈  𝐹 )  ∧  𝑞 ( 1st   ⊗  ( ( V  ∖   I  )  ∘  2nd  ) ) 𝑝 ) ) ) | 
						
							| 100 | 81 82 99 | 3bitr4ri | ⊢ ( 𝐹  ∈   Funs   ↔  Fun  𝐹 ) |