| Step | Hyp | Ref | Expression | 
						
							| 1 |  | frgrncvvdeq.v1 | ⊢ 𝑉  =  ( Vtx ‘ 𝐺 ) | 
						
							| 2 |  | frgrncvvdeq.e | ⊢ 𝐸  =  ( Edg ‘ 𝐺 ) | 
						
							| 3 |  | frgrncvvdeq.nx | ⊢ 𝐷  =  ( 𝐺  NeighbVtx  𝑋 ) | 
						
							| 4 |  | frgrncvvdeq.ny | ⊢ 𝑁  =  ( 𝐺  NeighbVtx  𝑌 ) | 
						
							| 5 |  | frgrncvvdeq.x | ⊢ ( 𝜑  →  𝑋  ∈  𝑉 ) | 
						
							| 6 |  | frgrncvvdeq.y | ⊢ ( 𝜑  →  𝑌  ∈  𝑉 ) | 
						
							| 7 |  | frgrncvvdeq.ne | ⊢ ( 𝜑  →  𝑋  ≠  𝑌 ) | 
						
							| 8 |  | frgrncvvdeq.xy | ⊢ ( 𝜑  →  𝑌  ∉  𝐷 ) | 
						
							| 9 |  | frgrncvvdeq.f | ⊢ ( 𝜑  →  𝐺  ∈   FriendGraph  ) | 
						
							| 10 |  | frgrncvvdeq.a | ⊢ 𝐴  =  ( 𝑥  ∈  𝐷  ↦  ( ℩ 𝑦  ∈  𝑁 { 𝑥 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 11 | 1 2 3 4 5 6 7 8 9 10 | frgrncvvdeqlem4 | ⊢ ( 𝜑  →  𝐴 : 𝐷 ⟶ 𝑁 ) | 
						
							| 12 |  | simpr | ⊢ ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  →  𝐴 : 𝐷 ⟶ 𝑁 ) | 
						
							| 13 |  | ffvelcdm | ⊢ ( ( 𝐴 : 𝐷 ⟶ 𝑁  ∧  𝑢  ∈  𝐷 )  →  ( 𝐴 ‘ 𝑢 )  ∈  𝑁 ) | 
						
							| 14 | 13 | ad2ant2lr | ⊢ ( ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( 𝐴 ‘ 𝑢 )  ∈  𝑁 ) | 
						
							| 15 | 14 | adantr | ⊢ ( ( ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  ∧  ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 ) )  →  ( 𝐴 ‘ 𝑢 )  ∈  𝑁 ) | 
						
							| 16 | 1 2 3 4 5 6 7 8 9 10 | frgrncvvdeqlem1 | ⊢ ( 𝜑  →  𝑋  ∉  𝑁 ) | 
						
							| 17 |  | preq1 | ⊢ ( 𝑥  =  𝑢  →  { 𝑥 ,  𝑦 }  =  { 𝑢 ,  𝑦 } ) | 
						
							| 18 | 17 | eleq1d | ⊢ ( 𝑥  =  𝑢  →  ( { 𝑥 ,  𝑦 }  ∈  𝐸  ↔  { 𝑢 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 19 | 18 | riotabidv | ⊢ ( 𝑥  =  𝑢  →  ( ℩ 𝑦  ∈  𝑁 { 𝑥 ,  𝑦 }  ∈  𝐸 )  =  ( ℩ 𝑦  ∈  𝑁 { 𝑢 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 20 | 19 | cbvmptv | ⊢ ( 𝑥  ∈  𝐷  ↦  ( ℩ 𝑦  ∈  𝑁 { 𝑥 ,  𝑦 }  ∈  𝐸 ) )  =  ( 𝑢  ∈  𝐷  ↦  ( ℩ 𝑦  ∈  𝑁 { 𝑢 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 21 | 10 20 | eqtri | ⊢ 𝐴  =  ( 𝑢  ∈  𝐷  ↦  ( ℩ 𝑦  ∈  𝑁 { 𝑢 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 22 | 1 2 3 4 5 6 7 8 9 21 | frgrncvvdeqlem6 | ⊢ ( ( 𝜑  ∧  𝑢  ∈  𝐷 )  →  { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 ) | 
						
							| 23 |  | preq1 | ⊢ ( 𝑥  =  𝑤  →  { 𝑥 ,  𝑦 }  =  { 𝑤 ,  𝑦 } ) | 
						
							| 24 | 23 | eleq1d | ⊢ ( 𝑥  =  𝑤  →  ( { 𝑥 ,  𝑦 }  ∈  𝐸  ↔  { 𝑤 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 25 | 24 | riotabidv | ⊢ ( 𝑥  =  𝑤  →  ( ℩ 𝑦  ∈  𝑁 { 𝑥 ,  𝑦 }  ∈  𝐸 )  =  ( ℩ 𝑦  ∈  𝑁 { 𝑤 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 26 | 25 | cbvmptv | ⊢ ( 𝑥  ∈  𝐷  ↦  ( ℩ 𝑦  ∈  𝑁 { 𝑥 ,  𝑦 }  ∈  𝐸 ) )  =  ( 𝑤  ∈  𝐷  ↦  ( ℩ 𝑦  ∈  𝑁 { 𝑤 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 27 | 10 26 | eqtri | ⊢ 𝐴  =  ( 𝑤  ∈  𝐷  ↦  ( ℩ 𝑦  ∈  𝑁 { 𝑤 ,  𝑦 }  ∈  𝐸 ) ) | 
						
							| 28 | 1 2 3 4 5 6 7 8 9 27 | frgrncvvdeqlem6 | ⊢ ( ( 𝜑  ∧  𝑤  ∈  𝐷 )  →  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸 ) | 
						
							| 29 | 22 28 | anim12dan | ⊢ ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸 ) ) | 
						
							| 30 |  | preq2 | ⊢ ( ( 𝐴 ‘ 𝑤 )  =  ( 𝐴 ‘ 𝑢 )  →  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  =  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) } ) | 
						
							| 31 | 30 | eleq1d | ⊢ ( ( 𝐴 ‘ 𝑤 )  =  ( 𝐴 ‘ 𝑢 )  →  ( { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸  ↔  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 ) ) | 
						
							| 32 | 31 | anbi2d | ⊢ ( ( 𝐴 ‘ 𝑤 )  =  ( 𝐴 ‘ 𝑢 )  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸 )  ↔  ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 ) ) ) | 
						
							| 33 | 32 | eqcoms | ⊢ ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸 )  ↔  ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 ) ) ) | 
						
							| 34 | 33 | biimpa | ⊢ ( ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  ∧  ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸 ) )  →  ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 ) ) | 
						
							| 35 |  | df-ne | ⊢ ( 𝑢  ≠  𝑤  ↔  ¬  𝑢  =  𝑤 ) | 
						
							| 36 | 2 3 | frgrnbnb | ⊢ ( ( 𝐺  ∈   FriendGraph   ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 )  ∧  𝑢  ≠  𝑤 )  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 )  →  ( 𝐴 ‘ 𝑢 )  =  𝑋 ) ) | 
						
							| 37 | 9 36 | syl3an1 | ⊢ ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 )  ∧  𝑢  ≠  𝑤 )  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 )  →  ( 𝐴 ‘ 𝑢 )  =  𝑋 ) ) | 
						
							| 38 | 37 | 3expa | ⊢ ( ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  ∧  𝑢  ≠  𝑤 )  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 )  →  ( 𝐴 ‘ 𝑢 )  =  𝑋 ) ) | 
						
							| 39 |  | df-nel | ⊢ ( 𝑋  ∉  𝑁  ↔  ¬  𝑋  ∈  𝑁 ) | 
						
							| 40 |  | eleq1 | ⊢ ( ( 𝐴 ‘ 𝑢 )  =  𝑋  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  ↔  𝑋  ∈  𝑁 ) ) | 
						
							| 41 | 40 | biimpa | ⊢ ( ( ( 𝐴 ‘ 𝑢 )  =  𝑋  ∧  ( 𝐴 ‘ 𝑢 )  ∈  𝑁 )  →  𝑋  ∈  𝑁 ) | 
						
							| 42 | 41 | pm2.24d | ⊢ ( ( ( 𝐴 ‘ 𝑢 )  =  𝑋  ∧  ( 𝐴 ‘ 𝑢 )  ∈  𝑁 )  →  ( ¬  𝑋  ∈  𝑁  →  𝑢  =  𝑤 ) ) | 
						
							| 43 | 42 | expcom | ⊢ ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  =  𝑋  →  ( ¬  𝑋  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) | 
						
							| 44 | 43 | com13 | ⊢ ( ¬  𝑋  ∈  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  =  𝑋  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) | 
						
							| 45 | 39 44 | sylbi | ⊢ ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  =  𝑋  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) | 
						
							| 46 | 45 | com12 | ⊢ ( ( 𝐴 ‘ 𝑢 )  =  𝑋  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) | 
						
							| 47 | 38 46 | syl6 | ⊢ ( ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  ∧  𝑢  ≠  𝑤 )  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) | 
						
							| 48 | 47 | expcom | ⊢ ( 𝑢  ≠  𝑤  →  ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) | 
						
							| 49 | 48 | com23 | ⊢ ( 𝑢  ≠  𝑤  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 )  →  ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) | 
						
							| 50 | 35 49 | sylbir | ⊢ ( ¬  𝑢  =  𝑤  →  ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸 )  →  ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) | 
						
							| 51 | 34 50 | syl5com | ⊢ ( ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  ∧  ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸 ) )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) | 
						
							| 52 | 51 | expcom | ⊢ ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸 )  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) ) | 
						
							| 53 | 52 | com24 | ⊢ ( ( { 𝑢 ,  ( 𝐴 ‘ 𝑢 ) }  ∈  𝐸  ∧  { 𝑤 ,  ( 𝐴 ‘ 𝑤 ) }  ∈  𝐸 )  →  ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) ) | 
						
							| 54 | 29 53 | mpcom | ⊢ ( ( 𝜑  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) | 
						
							| 55 | 54 | ex | ⊢ ( 𝜑  →  ( ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) ) | 
						
							| 56 | 55 | com3r | ⊢ ( ¬  𝑢  =  𝑤  →  ( 𝜑  →  ( ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 )  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( 𝑋  ∉  𝑁  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) ) | 
						
							| 57 | 56 | com15 | ⊢ ( 𝑋  ∉  𝑁  →  ( 𝜑  →  ( ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 )  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) ) | 
						
							| 58 | 16 57 | mpcom | ⊢ ( 𝜑  →  ( ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 )  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) | 
						
							| 59 | 58 | expd | ⊢ ( 𝜑  →  ( 𝑢  ∈  𝐷  →  ( 𝑤  ∈  𝐷  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) ) | 
						
							| 60 | 59 | adantr | ⊢ ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  →  ( 𝑢  ∈  𝐷  →  ( 𝑤  ∈  𝐷  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) ) ) ) | 
						
							| 61 | 60 | imp42 | ⊢ ( ( ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  ∧  ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 ) )  →  ( ¬  𝑢  =  𝑤  →  ( ( 𝐴 ‘ 𝑢 )  ∈  𝑁  →  𝑢  =  𝑤 ) ) ) | 
						
							| 62 | 15 61 | mpid | ⊢ ( ( ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  ∧  ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 ) )  →  ( ¬  𝑢  =  𝑤  →  𝑢  =  𝑤 ) ) | 
						
							| 63 | 62 | pm2.18d | ⊢ ( ( ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  ∧  ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 ) )  →  𝑢  =  𝑤 ) | 
						
							| 64 | 63 | ex | ⊢ ( ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  ∧  ( 𝑢  ∈  𝐷  ∧  𝑤  ∈  𝐷 ) )  →  ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  𝑢  =  𝑤 ) ) | 
						
							| 65 | 64 | ralrimivva | ⊢ ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  →  ∀ 𝑢  ∈  𝐷 ∀ 𝑤  ∈  𝐷 ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  𝑢  =  𝑤 ) ) | 
						
							| 66 |  | dff13 | ⊢ ( 𝐴 : 𝐷 –1-1→ 𝑁  ↔  ( 𝐴 : 𝐷 ⟶ 𝑁  ∧  ∀ 𝑢  ∈  𝐷 ∀ 𝑤  ∈  𝐷 ( ( 𝐴 ‘ 𝑢 )  =  ( 𝐴 ‘ 𝑤 )  →  𝑢  =  𝑤 ) ) ) | 
						
							| 67 | 12 65 66 | sylanbrc | ⊢ ( ( 𝜑  ∧  𝐴 : 𝐷 ⟶ 𝑁 )  →  𝐴 : 𝐷 –1-1→ 𝑁 ) | 
						
							| 68 | 11 67 | mpdan | ⊢ ( 𝜑  →  𝐴 : 𝐷 –1-1→ 𝑁 ) |