| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oveq1 |  |-  ( x = B -> ( x /L N ) = ( B /L N ) ) | 
						
							| 2 | 1 | oveq1d |  |-  ( x = B -> ( ( x /L N ) x. ( 0 /L N ) ) = ( ( B /L N ) x. ( 0 /L N ) ) ) | 
						
							| 3 | 2 | eqeq2d |  |-  ( x = B -> ( ( 0 /L N ) = ( ( x /L N ) x. ( 0 /L N ) ) <-> ( 0 /L N ) = ( ( B /L N ) x. ( 0 /L N ) ) ) ) | 
						
							| 4 |  | id |  |-  ( x e. ZZ -> x e. ZZ ) | 
						
							| 5 |  | nn0z |  |-  ( N e. NN0 -> N e. ZZ ) | 
						
							| 6 |  | lgscl |  |-  ( ( x e. ZZ /\ N e. ZZ ) -> ( x /L N ) e. ZZ ) | 
						
							| 7 | 4 5 6 | syl2anr |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( x /L N ) e. ZZ ) | 
						
							| 8 | 7 | zcnd |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( x /L N ) e. CC ) | 
						
							| 9 | 8 | adantr |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) = 0 ) -> ( x /L N ) e. CC ) | 
						
							| 10 | 9 | mul01d |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) = 0 ) -> ( ( x /L N ) x. 0 ) = 0 ) | 
						
							| 11 |  | simpr |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) = 0 ) -> ( 0 /L N ) = 0 ) | 
						
							| 12 | 11 | oveq2d |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) = 0 ) -> ( ( x /L N ) x. ( 0 /L N ) ) = ( ( x /L N ) x. 0 ) ) | 
						
							| 13 | 10 12 11 | 3eqtr4rd |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) = 0 ) -> ( 0 /L N ) = ( ( x /L N ) x. ( 0 /L N ) ) ) | 
						
							| 14 |  | 0z |  |-  0 e. ZZ | 
						
							| 15 | 5 | adantr |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> N e. ZZ ) | 
						
							| 16 |  | lgsne0 |  |-  ( ( 0 e. ZZ /\ N e. ZZ ) -> ( ( 0 /L N ) =/= 0 <-> ( 0 gcd N ) = 1 ) ) | 
						
							| 17 | 14 15 16 | sylancr |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( ( 0 /L N ) =/= 0 <-> ( 0 gcd N ) = 1 ) ) | 
						
							| 18 |  | gcdcom |  |-  ( ( 0 e. ZZ /\ N e. ZZ ) -> ( 0 gcd N ) = ( N gcd 0 ) ) | 
						
							| 19 | 14 15 18 | sylancr |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( 0 gcd N ) = ( N gcd 0 ) ) | 
						
							| 20 |  | nn0gcdid0 |  |-  ( N e. NN0 -> ( N gcd 0 ) = N ) | 
						
							| 21 | 20 | adantr |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( N gcd 0 ) = N ) | 
						
							| 22 | 19 21 | eqtrd |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( 0 gcd N ) = N ) | 
						
							| 23 | 22 | eqeq1d |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( ( 0 gcd N ) = 1 <-> N = 1 ) ) | 
						
							| 24 |  | lgs1 |  |-  ( x e. ZZ -> ( x /L 1 ) = 1 ) | 
						
							| 25 | 24 | adantl |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( x /L 1 ) = 1 ) | 
						
							| 26 |  | oveq2 |  |-  ( N = 1 -> ( x /L N ) = ( x /L 1 ) ) | 
						
							| 27 | 26 | eqeq1d |  |-  ( N = 1 -> ( ( x /L N ) = 1 <-> ( x /L 1 ) = 1 ) ) | 
						
							| 28 | 25 27 | syl5ibrcom |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( N = 1 -> ( x /L N ) = 1 ) ) | 
						
							| 29 | 23 28 | sylbid |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( ( 0 gcd N ) = 1 -> ( x /L N ) = 1 ) ) | 
						
							| 30 | 17 29 | sylbid |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( ( 0 /L N ) =/= 0 -> ( x /L N ) = 1 ) ) | 
						
							| 31 | 30 | imp |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) =/= 0 ) -> ( x /L N ) = 1 ) | 
						
							| 32 | 31 | oveq1d |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) =/= 0 ) -> ( ( x /L N ) x. ( 0 /L N ) ) = ( 1 x. ( 0 /L N ) ) ) | 
						
							| 33 | 5 | ad2antrr |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) =/= 0 ) -> N e. ZZ ) | 
						
							| 34 |  | lgscl |  |-  ( ( 0 e. ZZ /\ N e. ZZ ) -> ( 0 /L N ) e. ZZ ) | 
						
							| 35 | 14 33 34 | sylancr |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) =/= 0 ) -> ( 0 /L N ) e. ZZ ) | 
						
							| 36 | 35 | zcnd |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) =/= 0 ) -> ( 0 /L N ) e. CC ) | 
						
							| 37 | 36 | mullidd |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) =/= 0 ) -> ( 1 x. ( 0 /L N ) ) = ( 0 /L N ) ) | 
						
							| 38 | 32 37 | eqtr2d |  |-  ( ( ( N e. NN0 /\ x e. ZZ ) /\ ( 0 /L N ) =/= 0 ) -> ( 0 /L N ) = ( ( x /L N ) x. ( 0 /L N ) ) ) | 
						
							| 39 | 13 38 | pm2.61dane |  |-  ( ( N e. NN0 /\ x e. ZZ ) -> ( 0 /L N ) = ( ( x /L N ) x. ( 0 /L N ) ) ) | 
						
							| 40 | 39 | ralrimiva |  |-  ( N e. NN0 -> A. x e. ZZ ( 0 /L N ) = ( ( x /L N ) x. ( 0 /L N ) ) ) | 
						
							| 41 | 40 | 3ad2ant3 |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> A. x e. ZZ ( 0 /L N ) = ( ( x /L N ) x. ( 0 /L N ) ) ) | 
						
							| 42 |  | simp2 |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> B e. ZZ ) | 
						
							| 43 | 3 41 42 | rspcdva |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( 0 /L N ) = ( ( B /L N ) x. ( 0 /L N ) ) ) | 
						
							| 44 | 43 | adantr |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( 0 /L N ) = ( ( B /L N ) x. ( 0 /L N ) ) ) | 
						
							| 45 | 5 | 3ad2ant3 |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> N e. ZZ ) | 
						
							| 46 | 14 45 34 | sylancr |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( 0 /L N ) e. ZZ ) | 
						
							| 47 | 46 | zcnd |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( 0 /L N ) e. CC ) | 
						
							| 48 | 47 | adantr |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( 0 /L N ) e. CC ) | 
						
							| 49 |  | lgscl |  |-  ( ( B e. ZZ /\ N e. ZZ ) -> ( B /L N ) e. ZZ ) | 
						
							| 50 | 42 45 49 | syl2anc |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( B /L N ) e. ZZ ) | 
						
							| 51 | 50 | zcnd |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( B /L N ) e. CC ) | 
						
							| 52 | 51 | adantr |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( B /L N ) e. CC ) | 
						
							| 53 | 48 52 | mulcomd |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( ( 0 /L N ) x. ( B /L N ) ) = ( ( B /L N ) x. ( 0 /L N ) ) ) | 
						
							| 54 | 44 53 | eqtr4d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( 0 /L N ) = ( ( 0 /L N ) x. ( B /L N ) ) ) | 
						
							| 55 |  | oveq1 |  |-  ( A = 0 -> ( A x. B ) = ( 0 x. B ) ) | 
						
							| 56 |  | zcn |  |-  ( B e. ZZ -> B e. CC ) | 
						
							| 57 | 56 | 3ad2ant2 |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> B e. CC ) | 
						
							| 58 | 57 | mul02d |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( 0 x. B ) = 0 ) | 
						
							| 59 | 55 58 | sylan9eqr |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( A x. B ) = 0 ) | 
						
							| 60 | 59 | oveq1d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( ( A x. B ) /L N ) = ( 0 /L N ) ) | 
						
							| 61 |  | simpr |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> A = 0 ) | 
						
							| 62 | 61 | oveq1d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( A /L N ) = ( 0 /L N ) ) | 
						
							| 63 | 62 | oveq1d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( ( A /L N ) x. ( B /L N ) ) = ( ( 0 /L N ) x. ( B /L N ) ) ) | 
						
							| 64 | 54 60 63 | 3eqtr4d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ A = 0 ) -> ( ( A x. B ) /L N ) = ( ( A /L N ) x. ( B /L N ) ) ) | 
						
							| 65 |  | oveq1 |  |-  ( x = A -> ( x /L N ) = ( A /L N ) ) | 
						
							| 66 | 65 | oveq1d |  |-  ( x = A -> ( ( x /L N ) x. ( 0 /L N ) ) = ( ( A /L N ) x. ( 0 /L N ) ) ) | 
						
							| 67 | 66 | eqeq2d |  |-  ( x = A -> ( ( 0 /L N ) = ( ( x /L N ) x. ( 0 /L N ) ) <-> ( 0 /L N ) = ( ( A /L N ) x. ( 0 /L N ) ) ) ) | 
						
							| 68 |  | simp1 |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> A e. ZZ ) | 
						
							| 69 | 67 41 68 | rspcdva |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( 0 /L N ) = ( ( A /L N ) x. ( 0 /L N ) ) ) | 
						
							| 70 | 69 | adantr |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ B = 0 ) -> ( 0 /L N ) = ( ( A /L N ) x. ( 0 /L N ) ) ) | 
						
							| 71 |  | oveq2 |  |-  ( B = 0 -> ( A x. B ) = ( A x. 0 ) ) | 
						
							| 72 | 68 | zcnd |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> A e. CC ) | 
						
							| 73 | 72 | mul01d |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( A x. 0 ) = 0 ) | 
						
							| 74 | 71 73 | sylan9eqr |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ B = 0 ) -> ( A x. B ) = 0 ) | 
						
							| 75 | 74 | oveq1d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ B = 0 ) -> ( ( A x. B ) /L N ) = ( 0 /L N ) ) | 
						
							| 76 |  | simpr |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ B = 0 ) -> B = 0 ) | 
						
							| 77 | 76 | oveq1d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ B = 0 ) -> ( B /L N ) = ( 0 /L N ) ) | 
						
							| 78 | 77 | oveq2d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ B = 0 ) -> ( ( A /L N ) x. ( B /L N ) ) = ( ( A /L N ) x. ( 0 /L N ) ) ) | 
						
							| 79 | 70 75 78 | 3eqtr4d |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ B = 0 ) -> ( ( A x. B ) /L N ) = ( ( A /L N ) x. ( B /L N ) ) ) | 
						
							| 80 |  | lgsdir |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. ZZ ) /\ ( A =/= 0 /\ B =/= 0 ) ) -> ( ( A x. B ) /L N ) = ( ( A /L N ) x. ( B /L N ) ) ) | 
						
							| 81 | 5 80 | syl3anl3 |  |-  ( ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) /\ ( A =/= 0 /\ B =/= 0 ) ) -> ( ( A x. B ) /L N ) = ( ( A /L N ) x. ( B /L N ) ) ) | 
						
							| 82 | 64 79 81 | pm2.61da2ne |  |-  ( ( A e. ZZ /\ B e. ZZ /\ N e. NN0 ) -> ( ( A x. B ) /L N ) = ( ( A /L N ) x. ( B /L N ) ) ) |