| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elnn0 |  |-  ( A e. NN0 <-> ( A e. NN \/ A = 0 ) ) | 
						
							| 2 |  | elnn0 |  |-  ( B e. NN0 <-> ( B e. NN \/ B = 0 ) ) | 
						
							| 3 |  | expgcd |  |-  ( ( A e. NN /\ B e. NN /\ N e. NN0 ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 4 | 3 | 3expia |  |-  ( ( A e. NN /\ B e. NN ) -> ( N e. NN0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 5 |  | elnn0 |  |-  ( N e. NN0 <-> ( N e. NN \/ N = 0 ) ) | 
						
							| 6 |  | 0exp |  |-  ( N e. NN -> ( 0 ^ N ) = 0 ) | 
						
							| 7 | 6 | 3ad2ant3 |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( 0 ^ N ) = 0 ) | 
						
							| 8 | 7 | oveq1d |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( ( 0 ^ N ) gcd ( B ^ N ) ) = ( 0 gcd ( B ^ N ) ) ) | 
						
							| 9 |  | simp2 |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> B e. NN ) | 
						
							| 10 |  | nnnn0 |  |-  ( N e. NN -> N e. NN0 ) | 
						
							| 11 | 10 | 3ad2ant3 |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> N e. NN0 ) | 
						
							| 12 | 9 11 | nnexpcld |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( B ^ N ) e. NN ) | 
						
							| 13 | 12 | nnzd |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( B ^ N ) e. ZZ ) | 
						
							| 14 |  | gcd0id |  |-  ( ( B ^ N ) e. ZZ -> ( 0 gcd ( B ^ N ) ) = ( abs ` ( B ^ N ) ) ) | 
						
							| 15 | 13 14 | syl |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( 0 gcd ( B ^ N ) ) = ( abs ` ( B ^ N ) ) ) | 
						
							| 16 | 12 | nnred |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( B ^ N ) e. RR ) | 
						
							| 17 |  | 0red |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> 0 e. RR ) | 
						
							| 18 | 12 | nngt0d |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> 0 < ( B ^ N ) ) | 
						
							| 19 | 17 16 18 | ltled |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> 0 <_ ( B ^ N ) ) | 
						
							| 20 | 16 19 | absidd |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( abs ` ( B ^ N ) ) = ( B ^ N ) ) | 
						
							| 21 | 8 15 20 | 3eqtrrd |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( B ^ N ) = ( ( 0 ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 22 |  | oveq1 |  |-  ( A = 0 -> ( A gcd B ) = ( 0 gcd B ) ) | 
						
							| 23 | 22 | 3ad2ant1 |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( A gcd B ) = ( 0 gcd B ) ) | 
						
							| 24 |  | nnz |  |-  ( B e. NN -> B e. ZZ ) | 
						
							| 25 | 24 | 3ad2ant2 |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> B e. ZZ ) | 
						
							| 26 |  | gcd0id |  |-  ( B e. ZZ -> ( 0 gcd B ) = ( abs ` B ) ) | 
						
							| 27 | 25 26 | syl |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( 0 gcd B ) = ( abs ` B ) ) | 
						
							| 28 |  | nnre |  |-  ( B e. NN -> B e. RR ) | 
						
							| 29 |  | 0red |  |-  ( B e. NN -> 0 e. RR ) | 
						
							| 30 |  | nngt0 |  |-  ( B e. NN -> 0 < B ) | 
						
							| 31 | 29 28 30 | ltled |  |-  ( B e. NN -> 0 <_ B ) | 
						
							| 32 | 28 31 | absidd |  |-  ( B e. NN -> ( abs ` B ) = B ) | 
						
							| 33 | 32 | 3ad2ant2 |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( abs ` B ) = B ) | 
						
							| 34 | 23 27 33 | 3eqtrd |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( A gcd B ) = B ) | 
						
							| 35 | 34 | oveq1d |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( ( A gcd B ) ^ N ) = ( B ^ N ) ) | 
						
							| 36 |  | oveq1 |  |-  ( A = 0 -> ( A ^ N ) = ( 0 ^ N ) ) | 
						
							| 37 | 36 | 3ad2ant1 |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( A ^ N ) = ( 0 ^ N ) ) | 
						
							| 38 | 37 | oveq1d |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( ( A ^ N ) gcd ( B ^ N ) ) = ( ( 0 ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 39 | 21 35 38 | 3eqtr4d |  |-  ( ( A = 0 /\ B e. NN /\ N e. NN ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 40 | 39 | 3expia |  |-  ( ( A = 0 /\ B e. NN ) -> ( N e. NN -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 41 |  | 1z |  |-  1 e. ZZ | 
						
							| 42 |  | gcd1 |  |-  ( 1 e. ZZ -> ( 1 gcd 1 ) = 1 ) | 
						
							| 43 | 41 42 | ax-mp |  |-  ( 1 gcd 1 ) = 1 | 
						
							| 44 | 43 | eqcomi |  |-  1 = ( 1 gcd 1 ) | 
						
							| 45 |  | simp1 |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> A = 0 ) | 
						
							| 46 | 45 | oveq1d |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( A gcd B ) = ( 0 gcd B ) ) | 
						
							| 47 |  | simp2 |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> B e. NN ) | 
						
							| 48 | 47 | nnzd |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> B e. ZZ ) | 
						
							| 49 | 48 26 | syl |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( 0 gcd B ) = ( abs ` B ) ) | 
						
							| 50 | 32 | 3ad2ant2 |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( abs ` B ) = B ) | 
						
							| 51 | 46 49 50 | 3eqtrd |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( A gcd B ) = B ) | 
						
							| 52 |  | simp3 |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> N = 0 ) | 
						
							| 53 | 51 52 | oveq12d |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( B ^ 0 ) ) | 
						
							| 54 | 47 | nncnd |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> B e. CC ) | 
						
							| 55 | 54 | exp0d |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( B ^ 0 ) = 1 ) | 
						
							| 56 | 53 55 | eqtrd |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( ( A gcd B ) ^ N ) = 1 ) | 
						
							| 57 | 45 52 | oveq12d |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( A ^ N ) = ( 0 ^ 0 ) ) | 
						
							| 58 |  | 0exp0e1 |  |-  ( 0 ^ 0 ) = 1 | 
						
							| 59 | 58 | a1i |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( 0 ^ 0 ) = 1 ) | 
						
							| 60 | 57 59 | eqtrd |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( A ^ N ) = 1 ) | 
						
							| 61 | 52 | oveq2d |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( B ^ N ) = ( B ^ 0 ) ) | 
						
							| 62 | 61 55 | eqtrd |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( B ^ N ) = 1 ) | 
						
							| 63 | 60 62 | oveq12d |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( ( A ^ N ) gcd ( B ^ N ) ) = ( 1 gcd 1 ) ) | 
						
							| 64 | 44 56 63 | 3eqtr4a |  |-  ( ( A = 0 /\ B e. NN /\ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 65 | 64 | 3expia |  |-  ( ( A = 0 /\ B e. NN ) -> ( N = 0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 66 | 40 65 | jaod |  |-  ( ( A = 0 /\ B e. NN ) -> ( ( N e. NN \/ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 67 | 5 66 | biimtrid |  |-  ( ( A = 0 /\ B e. NN ) -> ( N e. NN0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 68 |  | nnnn0 |  |-  ( A e. NN -> A e. NN0 ) | 
						
							| 69 | 68 | 3ad2ant1 |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> A e. NN0 ) | 
						
							| 70 | 10 | 3ad2ant3 |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> N e. NN0 ) | 
						
							| 71 | 69 70 | nn0expcld |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( A ^ N ) e. NN0 ) | 
						
							| 72 |  | nn0gcdid0 |  |-  ( ( A ^ N ) e. NN0 -> ( ( A ^ N ) gcd 0 ) = ( A ^ N ) ) | 
						
							| 73 | 71 72 | syl |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( ( A ^ N ) gcd 0 ) = ( A ^ N ) ) | 
						
							| 74 |  | simp2 |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> B = 0 ) | 
						
							| 75 | 74 | oveq1d |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( B ^ N ) = ( 0 ^ N ) ) | 
						
							| 76 | 6 | 3ad2ant3 |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( 0 ^ N ) = 0 ) | 
						
							| 77 | 75 76 | eqtrd |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( B ^ N ) = 0 ) | 
						
							| 78 | 77 | oveq2d |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( ( A ^ N ) gcd ( B ^ N ) ) = ( ( A ^ N ) gcd 0 ) ) | 
						
							| 79 | 74 | oveq2d |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( A gcd B ) = ( A gcd 0 ) ) | 
						
							| 80 |  | nn0gcdid0 |  |-  ( A e. NN0 -> ( A gcd 0 ) = A ) | 
						
							| 81 | 68 80 | syl |  |-  ( A e. NN -> ( A gcd 0 ) = A ) | 
						
							| 82 | 81 | 3ad2ant1 |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( A gcd 0 ) = A ) | 
						
							| 83 | 79 82 | eqtrd |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( A gcd B ) = A ) | 
						
							| 84 | 83 | oveq1d |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( ( A gcd B ) ^ N ) = ( A ^ N ) ) | 
						
							| 85 | 73 78 84 | 3eqtr4rd |  |-  ( ( A e. NN /\ B = 0 /\ N e. NN ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 86 | 85 | 3expia |  |-  ( ( A e. NN /\ B = 0 ) -> ( N e. NN -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 87 |  | nncn |  |-  ( A e. NN -> A e. CC ) | 
						
							| 88 | 87 | exp0d |  |-  ( A e. NN -> ( A ^ 0 ) = 1 ) | 
						
							| 89 | 88 43 | eqtr4di |  |-  ( A e. NN -> ( A ^ 0 ) = ( 1 gcd 1 ) ) | 
						
							| 90 | 81 | oveq1d |  |-  ( A e. NN -> ( ( A gcd 0 ) ^ 0 ) = ( A ^ 0 ) ) | 
						
							| 91 | 58 | a1i |  |-  ( A e. NN -> ( 0 ^ 0 ) = 1 ) | 
						
							| 92 | 88 91 | oveq12d |  |-  ( A e. NN -> ( ( A ^ 0 ) gcd ( 0 ^ 0 ) ) = ( 1 gcd 1 ) ) | 
						
							| 93 | 89 90 92 | 3eqtr4d |  |-  ( A e. NN -> ( ( A gcd 0 ) ^ 0 ) = ( ( A ^ 0 ) gcd ( 0 ^ 0 ) ) ) | 
						
							| 94 | 93 | 3ad2ant1 |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> ( ( A gcd 0 ) ^ 0 ) = ( ( A ^ 0 ) gcd ( 0 ^ 0 ) ) ) | 
						
							| 95 |  | simp2 |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> B = 0 ) | 
						
							| 96 | 95 | oveq2d |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> ( A gcd B ) = ( A gcd 0 ) ) | 
						
							| 97 |  | simp3 |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> N = 0 ) | 
						
							| 98 | 96 97 | oveq12d |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( ( A gcd 0 ) ^ 0 ) ) | 
						
							| 99 | 97 | oveq2d |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> ( A ^ N ) = ( A ^ 0 ) ) | 
						
							| 100 | 95 97 | oveq12d |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> ( B ^ N ) = ( 0 ^ 0 ) ) | 
						
							| 101 | 99 100 | oveq12d |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> ( ( A ^ N ) gcd ( B ^ N ) ) = ( ( A ^ 0 ) gcd ( 0 ^ 0 ) ) ) | 
						
							| 102 | 94 98 101 | 3eqtr4d |  |-  ( ( A e. NN /\ B = 0 /\ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 103 | 102 | 3expia |  |-  ( ( A e. NN /\ B = 0 ) -> ( N = 0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 104 | 86 103 | jaod |  |-  ( ( A e. NN /\ B = 0 ) -> ( ( N e. NN \/ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 105 | 5 104 | biimtrid |  |-  ( ( A e. NN /\ B = 0 ) -> ( N e. NN0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 106 |  | gcd0val |  |-  ( 0 gcd 0 ) = 0 | 
						
							| 107 | 6 106 | eqtr4di |  |-  ( N e. NN -> ( 0 ^ N ) = ( 0 gcd 0 ) ) | 
						
							| 108 | 106 | a1i |  |-  ( N e. NN -> ( 0 gcd 0 ) = 0 ) | 
						
							| 109 | 108 | oveq1d |  |-  ( N e. NN -> ( ( 0 gcd 0 ) ^ N ) = ( 0 ^ N ) ) | 
						
							| 110 | 6 6 | oveq12d |  |-  ( N e. NN -> ( ( 0 ^ N ) gcd ( 0 ^ N ) ) = ( 0 gcd 0 ) ) | 
						
							| 111 | 107 109 110 | 3eqtr4d |  |-  ( N e. NN -> ( ( 0 gcd 0 ) ^ N ) = ( ( 0 ^ N ) gcd ( 0 ^ N ) ) ) | 
						
							| 112 | 111 | 3ad2ant3 |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> ( ( 0 gcd 0 ) ^ N ) = ( ( 0 ^ N ) gcd ( 0 ^ N ) ) ) | 
						
							| 113 |  | simp1 |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> A = 0 ) | 
						
							| 114 |  | simp2 |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> B = 0 ) | 
						
							| 115 | 113 114 | oveq12d |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> ( A gcd B ) = ( 0 gcd 0 ) ) | 
						
							| 116 | 115 | oveq1d |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> ( ( A gcd B ) ^ N ) = ( ( 0 gcd 0 ) ^ N ) ) | 
						
							| 117 | 113 | oveq1d |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> ( A ^ N ) = ( 0 ^ N ) ) | 
						
							| 118 | 114 | oveq1d |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> ( B ^ N ) = ( 0 ^ N ) ) | 
						
							| 119 | 117 118 | oveq12d |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> ( ( A ^ N ) gcd ( B ^ N ) ) = ( ( 0 ^ N ) gcd ( 0 ^ N ) ) ) | 
						
							| 120 | 112 116 119 | 3eqtr4d |  |-  ( ( A = 0 /\ B = 0 /\ N e. NN ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 121 | 120 | 3expia |  |-  ( ( A = 0 /\ B = 0 ) -> ( N e. NN -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 122 | 58 43 | eqtr4i |  |-  ( 0 ^ 0 ) = ( 1 gcd 1 ) | 
						
							| 123 | 106 | oveq1i |  |-  ( ( 0 gcd 0 ) ^ 0 ) = ( 0 ^ 0 ) | 
						
							| 124 | 58 58 | oveq12i |  |-  ( ( 0 ^ 0 ) gcd ( 0 ^ 0 ) ) = ( 1 gcd 1 ) | 
						
							| 125 | 122 123 124 | 3eqtr4i |  |-  ( ( 0 gcd 0 ) ^ 0 ) = ( ( 0 ^ 0 ) gcd ( 0 ^ 0 ) ) | 
						
							| 126 |  | simp1 |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> A = 0 ) | 
						
							| 127 |  | simp2 |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> B = 0 ) | 
						
							| 128 | 126 127 | oveq12d |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> ( A gcd B ) = ( 0 gcd 0 ) ) | 
						
							| 129 |  | simp3 |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> N = 0 ) | 
						
							| 130 | 128 129 | oveq12d |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( ( 0 gcd 0 ) ^ 0 ) ) | 
						
							| 131 | 126 129 | oveq12d |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> ( A ^ N ) = ( 0 ^ 0 ) ) | 
						
							| 132 | 127 129 | oveq12d |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> ( B ^ N ) = ( 0 ^ 0 ) ) | 
						
							| 133 | 131 132 | oveq12d |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> ( ( A ^ N ) gcd ( B ^ N ) ) = ( ( 0 ^ 0 ) gcd ( 0 ^ 0 ) ) ) | 
						
							| 134 | 125 130 133 | 3eqtr4a |  |-  ( ( A = 0 /\ B = 0 /\ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) | 
						
							| 135 | 134 | 3expia |  |-  ( ( A = 0 /\ B = 0 ) -> ( N = 0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 136 | 121 135 | jaod |  |-  ( ( A = 0 /\ B = 0 ) -> ( ( N e. NN \/ N = 0 ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 137 | 5 136 | biimtrid |  |-  ( ( A = 0 /\ B = 0 ) -> ( N e. NN0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 138 | 4 67 105 137 | ccase |  |-  ( ( ( A e. NN \/ A = 0 ) /\ ( B e. NN \/ B = 0 ) ) -> ( N e. NN0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 139 | 1 2 138 | syl2anb |  |-  ( ( A e. NN0 /\ B e. NN0 ) -> ( N e. NN0 -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) ) | 
						
							| 140 | 139 | 3impia |  |-  ( ( A e. NN0 /\ B e. NN0 /\ N e. NN0 ) -> ( ( A gcd B ) ^ N ) = ( ( A ^ N ) gcd ( B ^ N ) ) ) |