| Step | Hyp | Ref | Expression | 
						
							| 1 |  | nzss.m | ⊢ ( 𝜑  →  𝑀  ∈  ℤ ) | 
						
							| 2 |  | nzss.n | ⊢ ( 𝜑  →  𝑁  ∈  𝑉 ) | 
						
							| 3 |  | iddvds | ⊢ ( 𝑀  ∈  ℤ  →  𝑀  ∥  𝑀 ) | 
						
							| 4 |  | breq2 | ⊢ ( 𝑥  =  𝑀  →  ( 𝑀  ∥  𝑥  ↔  𝑀  ∥  𝑀 ) ) | 
						
							| 5 | 4 | elabg | ⊢ ( 𝑀  ∈  ℤ  →  ( 𝑀  ∈  { 𝑥  ∣  𝑀  ∥  𝑥 }  ↔  𝑀  ∥  𝑀 ) ) | 
						
							| 6 | 3 5 | mpbird | ⊢ ( 𝑀  ∈  ℤ  →  𝑀  ∈  { 𝑥  ∣  𝑀  ∥  𝑥 } ) | 
						
							| 7 |  | reldvds | ⊢ Rel   ∥ | 
						
							| 8 |  | relimasn | ⊢ ( Rel   ∥   →  (  ∥   “  { 𝑀 } )  =  { 𝑥  ∣  𝑀  ∥  𝑥 } ) | 
						
							| 9 | 7 8 | ax-mp | ⊢ (  ∥   “  { 𝑀 } )  =  { 𝑥  ∣  𝑀  ∥  𝑥 } | 
						
							| 10 | 6 9 | eleqtrrdi | ⊢ ( 𝑀  ∈  ℤ  →  𝑀  ∈  (  ∥   “  { 𝑀 } ) ) | 
						
							| 11 |  | ssel | ⊢ ( (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } )  →  ( 𝑀  ∈  (  ∥   “  { 𝑀 } )  →  𝑀  ∈  (  ∥   “  { 𝑁 } ) ) ) | 
						
							| 12 | 10 11 | syl5 | ⊢ ( (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } )  →  ( 𝑀  ∈  ℤ  →  𝑀  ∈  (  ∥   “  { 𝑁 } ) ) ) | 
						
							| 13 |  | breq2 | ⊢ ( 𝑥  =  𝑀  →  ( 𝑁  ∥  𝑥  ↔  𝑁  ∥  𝑀 ) ) | 
						
							| 14 |  | relimasn | ⊢ ( Rel   ∥   →  (  ∥   “  { 𝑁 } )  =  { 𝑥  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 15 | 7 14 | ax-mp | ⊢ (  ∥   “  { 𝑁 } )  =  { 𝑥  ∣  𝑁  ∥  𝑥 } | 
						
							| 16 | 13 15 | elab2g | ⊢ ( 𝑀  ∈  ℤ  →  ( 𝑀  ∈  (  ∥   “  { 𝑁 } )  ↔  𝑁  ∥  𝑀 ) ) | 
						
							| 17 | 12 16 | mpbidi | ⊢ ( (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } )  →  ( 𝑀  ∈  ℤ  →  𝑁  ∥  𝑀 ) ) | 
						
							| 18 | 17 | com12 | ⊢ ( 𝑀  ∈  ℤ  →  ( (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } )  →  𝑁  ∥  𝑀 ) ) | 
						
							| 19 | 18 | adantr | ⊢ ( ( 𝑀  ∈  ℤ  ∧  𝑁  ∈  𝑉 )  →  ( (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } )  →  𝑁  ∥  𝑀 ) ) | 
						
							| 20 |  | ssid | ⊢ { 0 }  ⊆  { 0 } | 
						
							| 21 |  | simpl | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  𝑁  ∥  𝑀 ) | 
						
							| 22 |  | breq1 | ⊢ ( 𝑁  =  0  →  ( 𝑁  ∥  𝑀  ↔  0  ∥  𝑀 ) ) | 
						
							| 23 |  | dvdszrcl | ⊢ ( 𝑁  ∥  𝑀  →  ( 𝑁  ∈  ℤ  ∧  𝑀  ∈  ℤ ) ) | 
						
							| 24 | 23 | simprd | ⊢ ( 𝑁  ∥  𝑀  →  𝑀  ∈  ℤ ) | 
						
							| 25 |  | 0dvds | ⊢ ( 𝑀  ∈  ℤ  →  ( 0  ∥  𝑀  ↔  𝑀  =  0 ) ) | 
						
							| 26 | 24 25 | syl | ⊢ ( 𝑁  ∥  𝑀  →  ( 0  ∥  𝑀  ↔  𝑀  =  0 ) ) | 
						
							| 27 | 22 26 | sylan9bbr | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  ( 𝑁  ∥  𝑀  ↔  𝑀  =  0 ) ) | 
						
							| 28 | 21 27 | mpbid | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  𝑀  =  0 ) | 
						
							| 29 | 28 | breq1d | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  ( 𝑀  ∥  𝑥  ↔  0  ∥  𝑥 ) ) | 
						
							| 30 |  | 0dvds | ⊢ ( 𝑥  ∈  ℤ  →  ( 0  ∥  𝑥  ↔  𝑥  =  0 ) ) | 
						
							| 31 | 29 30 | sylan9bb | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  ∧  𝑥  ∈  ℤ )  →  ( 𝑀  ∥  𝑥  ↔  𝑥  =  0 ) ) | 
						
							| 32 | 31 | rabbidva | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  =  { 𝑥  ∈  ℤ  ∣  𝑥  =  0 } ) | 
						
							| 33 |  | 0z | ⊢ 0  ∈  ℤ | 
						
							| 34 |  | rabsn | ⊢ ( 0  ∈  ℤ  →  { 𝑥  ∈  ℤ  ∣  𝑥  =  0 }  =  { 0 } ) | 
						
							| 35 | 33 34 | ax-mp | ⊢ { 𝑥  ∈  ℤ  ∣  𝑥  =  0 }  =  { 0 } | 
						
							| 36 | 32 35 | eqtrdi | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  =  { 0 } ) | 
						
							| 37 |  | breq1 | ⊢ ( 𝑁  =  0  →  ( 𝑁  ∥  𝑥  ↔  0  ∥  𝑥 ) ) | 
						
							| 38 | 37 | rabbidv | ⊢ ( 𝑁  =  0  →  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 }  =  { 𝑥  ∈  ℤ  ∣  0  ∥  𝑥 } ) | 
						
							| 39 | 30 | rabbiia | ⊢ { 𝑥  ∈  ℤ  ∣  0  ∥  𝑥 }  =  { 𝑥  ∈  ℤ  ∣  𝑥  =  0 } | 
						
							| 40 | 39 35 | eqtri | ⊢ { 𝑥  ∈  ℤ  ∣  0  ∥  𝑥 }  =  { 0 } | 
						
							| 41 | 38 40 | eqtrdi | ⊢ ( 𝑁  =  0  →  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 }  =  { 0 } ) | 
						
							| 42 | 41 | adantl | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 }  =  { 0 } ) | 
						
							| 43 | 36 42 | sseq12d | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  ( { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  ⊆  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 }  ↔  { 0 }  ⊆  { 0 } ) ) | 
						
							| 44 | 20 43 | mpbiri | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  =  0 )  →  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  ⊆  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 45 | 24 | zcnd | ⊢ ( 𝑁  ∥  𝑀  →  𝑀  ∈  ℂ ) | 
						
							| 46 | 45 | ad2antrr | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  ∧  𝑛  ∈  ℤ )  →  𝑀  ∈  ℂ ) | 
						
							| 47 | 23 | simpld | ⊢ ( 𝑁  ∥  𝑀  →  𝑁  ∈  ℤ ) | 
						
							| 48 | 47 | zcnd | ⊢ ( 𝑁  ∥  𝑀  →  𝑁  ∈  ℂ ) | 
						
							| 49 | 48 | ad2antrr | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  ∧  𝑛  ∈  ℤ )  →  𝑁  ∈  ℂ ) | 
						
							| 50 |  | simplr | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  ∧  𝑛  ∈  ℤ )  →  𝑁  ≠  0 ) | 
						
							| 51 | 46 49 50 | divcan2d | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  ∧  𝑛  ∈  ℤ )  →  ( 𝑁  ·  ( 𝑀  /  𝑁 ) )  =  𝑀 ) | 
						
							| 52 | 51 | breq1d | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  ∧  𝑛  ∈  ℤ )  →  ( ( 𝑁  ·  ( 𝑀  /  𝑁 ) )  ∥  𝑛  ↔  𝑀  ∥  𝑛 ) ) | 
						
							| 53 | 47 | adantr | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  →  𝑁  ∈  ℤ ) | 
						
							| 54 |  | dvdsval2 | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑁  ≠  0  ∧  𝑀  ∈  ℤ )  →  ( 𝑁  ∥  𝑀  ↔  ( 𝑀  /  𝑁 )  ∈  ℤ ) ) | 
						
							| 55 | 54 | biimpd | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑁  ≠  0  ∧  𝑀  ∈  ℤ )  →  ( 𝑁  ∥  𝑀  →  ( 𝑀  /  𝑁 )  ∈  ℤ ) ) | 
						
							| 56 | 55 | 3com23 | ⊢ ( ( 𝑁  ∈  ℤ  ∧  𝑀  ∈  ℤ  ∧  𝑁  ≠  0 )  →  ( 𝑁  ∥  𝑀  →  ( 𝑀  /  𝑁 )  ∈  ℤ ) ) | 
						
							| 57 | 56 | 3expa | ⊢ ( ( ( 𝑁  ∈  ℤ  ∧  𝑀  ∈  ℤ )  ∧  𝑁  ≠  0 )  →  ( 𝑁  ∥  𝑀  →  ( 𝑀  /  𝑁 )  ∈  ℤ ) ) | 
						
							| 58 | 23 57 | sylan | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  →  ( 𝑁  ∥  𝑀  →  ( 𝑀  /  𝑁 )  ∈  ℤ ) ) | 
						
							| 59 | 58 | imp | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  ∧  𝑁  ∥  𝑀 )  →  ( 𝑀  /  𝑁 )  ∈  ℤ ) | 
						
							| 60 | 59 | anabss1 | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  →  ( 𝑀  /  𝑁 )  ∈  ℤ ) | 
						
							| 61 | 53 60 | jca | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  →  ( 𝑁  ∈  ℤ  ∧  ( 𝑀  /  𝑁 )  ∈  ℤ ) ) | 
						
							| 62 |  | muldvds1 | ⊢ ( ( 𝑁  ∈  ℤ  ∧  ( 𝑀  /  𝑁 )  ∈  ℤ  ∧  𝑛  ∈  ℤ )  →  ( ( 𝑁  ·  ( 𝑀  /  𝑁 ) )  ∥  𝑛  →  𝑁  ∥  𝑛 ) ) | 
						
							| 63 | 62 | 3expa | ⊢ ( ( ( 𝑁  ∈  ℤ  ∧  ( 𝑀  /  𝑁 )  ∈  ℤ )  ∧  𝑛  ∈  ℤ )  →  ( ( 𝑁  ·  ( 𝑀  /  𝑁 ) )  ∥  𝑛  →  𝑁  ∥  𝑛 ) ) | 
						
							| 64 | 61 63 | sylan | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  ∧  𝑛  ∈  ℤ )  →  ( ( 𝑁  ·  ( 𝑀  /  𝑁 ) )  ∥  𝑛  →  𝑁  ∥  𝑛 ) ) | 
						
							| 65 | 52 64 | sylbird | ⊢ ( ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  ∧  𝑛  ∈  ℤ )  →  ( 𝑀  ∥  𝑛  →  𝑁  ∥  𝑛 ) ) | 
						
							| 66 | 65 | ss2rabdv | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  →  { 𝑛  ∈  ℤ  ∣  𝑀  ∥  𝑛 }  ⊆  { 𝑛  ∈  ℤ  ∣  𝑁  ∥  𝑛 } ) | 
						
							| 67 |  | breq2 | ⊢ ( 𝑛  =  𝑥  →  ( 𝑀  ∥  𝑛  ↔  𝑀  ∥  𝑥 ) ) | 
						
							| 68 | 67 | cbvrabv | ⊢ { 𝑛  ∈  ℤ  ∣  𝑀  ∥  𝑛 }  =  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 } | 
						
							| 69 |  | breq2 | ⊢ ( 𝑛  =  𝑥  →  ( 𝑁  ∥  𝑛  ↔  𝑁  ∥  𝑥 ) ) | 
						
							| 70 | 69 | cbvrabv | ⊢ { 𝑛  ∈  ℤ  ∣  𝑁  ∥  𝑛 }  =  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 } | 
						
							| 71 | 66 68 70 | 3sstr3g | ⊢ ( ( 𝑁  ∥  𝑀  ∧  𝑁  ≠  0 )  →  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  ⊆  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 72 | 44 71 | pm2.61dane | ⊢ ( 𝑁  ∥  𝑀  →  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  ⊆  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 73 |  | breq1 | ⊢ ( 𝑛  =  𝑀  →  ( 𝑛  ∥  𝑥  ↔  𝑀  ∥  𝑥 ) ) | 
						
							| 74 | 73 | rabbidv | ⊢ ( 𝑛  =  𝑀  →  { 𝑥  ∈  ℤ  ∣  𝑛  ∥  𝑥 }  =  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 } ) | 
						
							| 75 | 73 | abbidv | ⊢ ( 𝑛  =  𝑀  →  { 𝑥  ∣  𝑛  ∥  𝑥 }  =  { 𝑥  ∣  𝑀  ∥  𝑥 } ) | 
						
							| 76 | 74 75 | eqeq12d | ⊢ ( 𝑛  =  𝑀  →  ( { 𝑥  ∈  ℤ  ∣  𝑛  ∥  𝑥 }  =  { 𝑥  ∣  𝑛  ∥  𝑥 }  ↔  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  =  { 𝑥  ∣  𝑀  ∥  𝑥 } ) ) | 
						
							| 77 |  | simpr | ⊢ ( ( 𝑦  ∈  ℤ  ∧  𝑛  ∥  𝑦 )  →  𝑛  ∥  𝑦 ) | 
						
							| 78 |  | dvdszrcl | ⊢ ( 𝑛  ∥  𝑦  →  ( 𝑛  ∈  ℤ  ∧  𝑦  ∈  ℤ ) ) | 
						
							| 79 | 78 | simprd | ⊢ ( 𝑛  ∥  𝑦  →  𝑦  ∈  ℤ ) | 
						
							| 80 | 79 | ancri | ⊢ ( 𝑛  ∥  𝑦  →  ( 𝑦  ∈  ℤ  ∧  𝑛  ∥  𝑦 ) ) | 
						
							| 81 | 77 80 | impbii | ⊢ ( ( 𝑦  ∈  ℤ  ∧  𝑛  ∥  𝑦 )  ↔  𝑛  ∥  𝑦 ) | 
						
							| 82 |  | breq2 | ⊢ ( 𝑥  =  𝑦  →  ( 𝑛  ∥  𝑥  ↔  𝑛  ∥  𝑦 ) ) | 
						
							| 83 | 82 | elrab | ⊢ ( 𝑦  ∈  { 𝑥  ∈  ℤ  ∣  𝑛  ∥  𝑥 }  ↔  ( 𝑦  ∈  ℤ  ∧  𝑛  ∥  𝑦 ) ) | 
						
							| 84 |  | vex | ⊢ 𝑦  ∈  V | 
						
							| 85 | 84 82 | elab | ⊢ ( 𝑦  ∈  { 𝑥  ∣  𝑛  ∥  𝑥 }  ↔  𝑛  ∥  𝑦 ) | 
						
							| 86 | 81 83 85 | 3bitr4i | ⊢ ( 𝑦  ∈  { 𝑥  ∈  ℤ  ∣  𝑛  ∥  𝑥 }  ↔  𝑦  ∈  { 𝑥  ∣  𝑛  ∥  𝑥 } ) | 
						
							| 87 | 86 | eqriv | ⊢ { 𝑥  ∈  ℤ  ∣  𝑛  ∥  𝑥 }  =  { 𝑥  ∣  𝑛  ∥  𝑥 } | 
						
							| 88 | 76 87 | vtoclg | ⊢ ( 𝑀  ∈  ℤ  →  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  =  { 𝑥  ∣  𝑀  ∥  𝑥 } ) | 
						
							| 89 | 88 | adantr | ⊢ ( ( 𝑀  ∈  ℤ  ∧  𝑁  ∈  𝑉 )  →  { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  =  { 𝑥  ∣  𝑀  ∥  𝑥 } ) | 
						
							| 90 |  | breq1 | ⊢ ( 𝑛  =  𝑁  →  ( 𝑛  ∥  𝑥  ↔  𝑁  ∥  𝑥 ) ) | 
						
							| 91 | 90 | rabbidv | ⊢ ( 𝑛  =  𝑁  →  { 𝑥  ∈  ℤ  ∣  𝑛  ∥  𝑥 }  =  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 92 | 90 | abbidv | ⊢ ( 𝑛  =  𝑁  →  { 𝑥  ∣  𝑛  ∥  𝑥 }  =  { 𝑥  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 93 | 91 92 | eqeq12d | ⊢ ( 𝑛  =  𝑁  →  ( { 𝑥  ∈  ℤ  ∣  𝑛  ∥  𝑥 }  =  { 𝑥  ∣  𝑛  ∥  𝑥 }  ↔  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 }  =  { 𝑥  ∣  𝑁  ∥  𝑥 } ) ) | 
						
							| 94 | 93 87 | vtoclg | ⊢ ( 𝑁  ∈  𝑉  →  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 }  =  { 𝑥  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 95 | 94 | adantl | ⊢ ( ( 𝑀  ∈  ℤ  ∧  𝑁  ∈  𝑉 )  →  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 }  =  { 𝑥  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 96 | 89 95 | sseq12d | ⊢ ( ( 𝑀  ∈  ℤ  ∧  𝑁  ∈  𝑉 )  →  ( { 𝑥  ∈  ℤ  ∣  𝑀  ∥  𝑥 }  ⊆  { 𝑥  ∈  ℤ  ∣  𝑁  ∥  𝑥 }  ↔  { 𝑥  ∣  𝑀  ∥  𝑥 }  ⊆  { 𝑥  ∣  𝑁  ∥  𝑥 } ) ) | 
						
							| 97 | 72 96 | imbitrid | ⊢ ( ( 𝑀  ∈  ℤ  ∧  𝑁  ∈  𝑉 )  →  ( 𝑁  ∥  𝑀  →  { 𝑥  ∣  𝑀  ∥  𝑥 }  ⊆  { 𝑥  ∣  𝑁  ∥  𝑥 } ) ) | 
						
							| 98 | 9 15 | sseq12i | ⊢ ( (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } )  ↔  { 𝑥  ∣  𝑀  ∥  𝑥 }  ⊆  { 𝑥  ∣  𝑁  ∥  𝑥 } ) | 
						
							| 99 | 97 98 | imbitrrdi | ⊢ ( ( 𝑀  ∈  ℤ  ∧  𝑁  ∈  𝑉 )  →  ( 𝑁  ∥  𝑀  →  (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } ) ) ) | 
						
							| 100 | 19 99 | impbid | ⊢ ( ( 𝑀  ∈  ℤ  ∧  𝑁  ∈  𝑉 )  →  ( (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } )  ↔  𝑁  ∥  𝑀 ) ) | 
						
							| 101 | 1 2 100 | syl2anc | ⊢ ( 𝜑  →  ( (  ∥   “  { 𝑀 } )  ⊆  (  ∥   “  { 𝑁 } )  ↔  𝑁  ∥  𝑀 ) ) |