| Step | Hyp | Ref | Expression | 
						
							| 1 |  | nna4b4nsq.a |  |-  ( ph -> A e. NN ) | 
						
							| 2 |  | nna4b4nsq.b |  |-  ( ph -> B e. NN ) | 
						
							| 3 |  | nna4b4nsq.c |  |-  ( ph -> C e. NN ) | 
						
							| 4 |  | oveq1 |  |-  ( a = A -> ( a ^ 4 ) = ( A ^ 4 ) ) | 
						
							| 5 | 4 | oveq1d |  |-  ( a = A -> ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( ( A ^ 4 ) + ( b ^ 4 ) ) ) | 
						
							| 6 | 5 | eqeq1d |  |-  ( a = A -> ( ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) <-> ( ( A ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) | 
						
							| 7 |  | oveq1 |  |-  ( b = B -> ( b ^ 4 ) = ( B ^ 4 ) ) | 
						
							| 8 | 7 | oveq2d |  |-  ( b = B -> ( ( A ^ 4 ) + ( b ^ 4 ) ) = ( ( A ^ 4 ) + ( B ^ 4 ) ) ) | 
						
							| 9 | 8 | eqeq1d |  |-  ( b = B -> ( ( ( A ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) <-> ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) ) ) | 
						
							| 10 | 1 | ad2antrr |  |-  ( ( ( ph /\ c e. NN ) /\ ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) ) -> A e. NN ) | 
						
							| 11 | 2 | ad2antrr |  |-  ( ( ( ph /\ c e. NN ) /\ ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) ) -> B e. NN ) | 
						
							| 12 |  | simpr |  |-  ( ( ( ph /\ c e. NN ) /\ ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) ) -> ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) ) | 
						
							| 13 | 6 9 10 11 12 | 2rspcedvdw |  |-  ( ( ( ph /\ c e. NN ) /\ ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) ) -> E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) | 
						
							| 14 | 13 | ex |  |-  ( ( ph /\ c e. NN ) -> ( ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) -> E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) | 
						
							| 15 | 14 | ss2rabdv |  |-  ( ph -> { c e. NN | ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) } C_ { c e. NN | E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) } ) | 
						
							| 16 |  | oveq1 |  |-  ( f = i -> ( f ^ 2 ) = ( i ^ 2 ) ) | 
						
							| 17 | 16 | eqeq2d |  |-  ( f = i -> ( ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) <-> ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) | 
						
							| 18 | 17 | anbi2d |  |-  ( f = i -> ( ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) <-> ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) ) | 
						
							| 19 | 18 | anbi2d |  |-  ( f = i -> ( ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) ) ) | 
						
							| 20 | 19 | 2rexbidv |  |-  ( f = i -> ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) ) ) | 
						
							| 21 |  | oveq1 |  |-  ( f = l -> ( f ^ 2 ) = ( l ^ 2 ) ) | 
						
							| 22 | 21 | eqeq2d |  |-  ( f = l -> ( ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) <-> ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) | 
						
							| 23 | 22 | anbi2d |  |-  ( f = l -> ( ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) <-> ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) ) | 
						
							| 24 | 23 | anbi2d |  |-  ( f = l -> ( ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) ) ) | 
						
							| 25 | 24 | 2rexbidv |  |-  ( f = l -> ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) ) ) | 
						
							| 26 |  | nnuz |  |-  NN = ( ZZ>= ` 1 ) | 
						
							| 27 | 26 | eqimssi |  |-  NN C_ ( ZZ>= ` 1 ) | 
						
							| 28 | 27 | a1i |  |-  ( ph -> NN C_ ( ZZ>= ` 1 ) ) | 
						
							| 29 |  | breq2 |  |-  ( g = j -> ( 2 || g <-> 2 || j ) ) | 
						
							| 30 | 29 | notbid |  |-  ( g = j -> ( -. 2 || g <-> -. 2 || j ) ) | 
						
							| 31 |  | oveq1 |  |-  ( g = j -> ( g gcd h ) = ( j gcd h ) ) | 
						
							| 32 | 31 | eqeq1d |  |-  ( g = j -> ( ( g gcd h ) = 1 <-> ( j gcd h ) = 1 ) ) | 
						
							| 33 |  | oveq1 |  |-  ( g = j -> ( g ^ 4 ) = ( j ^ 4 ) ) | 
						
							| 34 | 33 | oveq1d |  |-  ( g = j -> ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( ( j ^ 4 ) + ( h ^ 4 ) ) ) | 
						
							| 35 | 34 | eqeq1d |  |-  ( g = j -> ( ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) <-> ( ( j ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) | 
						
							| 36 | 32 35 | anbi12d |  |-  ( g = j -> ( ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) <-> ( ( j gcd h ) = 1 /\ ( ( j ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) ) | 
						
							| 37 | 30 36 | anbi12d |  |-  ( g = j -> ( ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) <-> ( -. 2 || j /\ ( ( j gcd h ) = 1 /\ ( ( j ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) ) ) | 
						
							| 38 |  | oveq2 |  |-  ( h = k -> ( j gcd h ) = ( j gcd k ) ) | 
						
							| 39 | 38 | eqeq1d |  |-  ( h = k -> ( ( j gcd h ) = 1 <-> ( j gcd k ) = 1 ) ) | 
						
							| 40 |  | oveq1 |  |-  ( h = k -> ( h ^ 4 ) = ( k ^ 4 ) ) | 
						
							| 41 | 40 | oveq2d |  |-  ( h = k -> ( ( j ^ 4 ) + ( h ^ 4 ) ) = ( ( j ^ 4 ) + ( k ^ 4 ) ) ) | 
						
							| 42 | 41 | eqeq1d |  |-  ( h = k -> ( ( ( j ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) <-> ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) | 
						
							| 43 | 39 42 | anbi12d |  |-  ( h = k -> ( ( ( j gcd h ) = 1 /\ ( ( j ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) <-> ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) | 
						
							| 44 | 43 | anbi2d |  |-  ( h = k -> ( ( -. 2 || j /\ ( ( j gcd h ) = 1 /\ ( ( j ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) <-> ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) ) | 
						
							| 45 | 37 44 | cbvrex2vw |  |-  ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) <-> E. j e. NN E. k e. NN ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) | 
						
							| 46 |  | simplrl |  |-  ( ( ( ( ph /\ i e. NN ) /\ ( j e. NN /\ k e. NN ) ) /\ ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) -> j e. NN ) | 
						
							| 47 |  | simplrr |  |-  ( ( ( ( ph /\ i e. NN ) /\ ( j e. NN /\ k e. NN ) ) /\ ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) -> k e. NN ) | 
						
							| 48 |  | simpllr |  |-  ( ( ( ( ph /\ i e. NN ) /\ ( j e. NN /\ k e. NN ) ) /\ ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) -> i e. NN ) | 
						
							| 49 |  | simprl |  |-  ( ( ( ( ph /\ i e. NN ) /\ ( j e. NN /\ k e. NN ) ) /\ ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) -> -. 2 || j ) | 
						
							| 50 |  | simprrl |  |-  ( ( ( ( ph /\ i e. NN ) /\ ( j e. NN /\ k e. NN ) ) /\ ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) -> ( j gcd k ) = 1 ) | 
						
							| 51 |  | simprrr |  |-  ( ( ( ( ph /\ i e. NN ) /\ ( j e. NN /\ k e. NN ) ) /\ ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) -> ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) | 
						
							| 52 | 46 47 48 49 50 51 | flt4lem7 |  |-  ( ( ( ( ph /\ i e. NN ) /\ ( j e. NN /\ k e. NN ) ) /\ ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) ) -> E. l e. NN ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) /\ l < i ) ) | 
						
							| 53 | 52 | ex |  |-  ( ( ( ph /\ i e. NN ) /\ ( j e. NN /\ k e. NN ) ) -> ( ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) -> E. l e. NN ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) /\ l < i ) ) ) | 
						
							| 54 | 53 | rexlimdvva |  |-  ( ( ph /\ i e. NN ) -> ( E. j e. NN E. k e. NN ( -. 2 || j /\ ( ( j gcd k ) = 1 /\ ( ( j ^ 4 ) + ( k ^ 4 ) ) = ( i ^ 2 ) ) ) -> E. l e. NN ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) /\ l < i ) ) ) | 
						
							| 55 | 45 54 | biimtrid |  |-  ( ( ph /\ i e. NN ) -> ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) -> E. l e. NN ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) /\ l < i ) ) ) | 
						
							| 56 | 55 | impr |  |-  ( ( ph /\ ( i e. NN /\ E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( i ^ 2 ) ) ) ) ) -> E. l e. NN ( E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( l ^ 2 ) ) ) /\ l < i ) ) | 
						
							| 57 | 20 25 28 56 | infdesc |  |-  ( ph -> { f e. NN | E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) } = (/) ) | 
						
							| 58 |  | breq2 |  |-  ( g = d -> ( 2 || g <-> 2 || d ) ) | 
						
							| 59 | 58 | notbid |  |-  ( g = d -> ( -. 2 || g <-> -. 2 || d ) ) | 
						
							| 60 |  | oveq1 |  |-  ( g = d -> ( g gcd h ) = ( d gcd h ) ) | 
						
							| 61 | 60 | eqeq1d |  |-  ( g = d -> ( ( g gcd h ) = 1 <-> ( d gcd h ) = 1 ) ) | 
						
							| 62 |  | oveq1 |  |-  ( g = d -> ( g ^ 4 ) = ( d ^ 4 ) ) | 
						
							| 63 | 62 | oveq1d |  |-  ( g = d -> ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( ( d ^ 4 ) + ( h ^ 4 ) ) ) | 
						
							| 64 | 63 | eqeq1d |  |-  ( g = d -> ( ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) <-> ( ( d ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) | 
						
							| 65 | 61 64 | anbi12d |  |-  ( g = d -> ( ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) <-> ( ( d gcd h ) = 1 /\ ( ( d ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 66 | 59 65 | anbi12d |  |-  ( g = d -> ( ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> ( -. 2 || d /\ ( ( d gcd h ) = 1 /\ ( ( d ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) ) | 
						
							| 67 |  | oveq2 |  |-  ( h = e -> ( d gcd h ) = ( d gcd e ) ) | 
						
							| 68 | 67 | eqeq1d |  |-  ( h = e -> ( ( d gcd h ) = 1 <-> ( d gcd e ) = 1 ) ) | 
						
							| 69 |  | oveq1 |  |-  ( h = e -> ( h ^ 4 ) = ( e ^ 4 ) ) | 
						
							| 70 | 69 | oveq2d |  |-  ( h = e -> ( ( d ^ 4 ) + ( h ^ 4 ) ) = ( ( d ^ 4 ) + ( e ^ 4 ) ) ) | 
						
							| 71 | 70 | eqeq1d |  |-  ( h = e -> ( ( ( d ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) <-> ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) | 
						
							| 72 | 68 71 | anbi12d |  |-  ( h = e -> ( ( ( d gcd h ) = 1 /\ ( ( d ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) <-> ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 73 | 72 | anbi2d |  |-  ( h = e -> ( ( -. 2 || d /\ ( ( d gcd h ) = 1 /\ ( ( d ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> ( -. 2 || d /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) ) ) | 
						
							| 74 |  | simprl |  |-  ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) -> d e. NN ) | 
						
							| 75 | 74 | ad2antrr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || d ) -> d e. NN ) | 
						
							| 76 |  | simprr |  |-  ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) -> e e. NN ) | 
						
							| 77 | 76 | ad2antrr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || d ) -> e e. NN ) | 
						
							| 78 |  | simpr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || d ) -> -. 2 || d ) | 
						
							| 79 |  | simplr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || d ) -> ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) | 
						
							| 80 | 78 79 | jca |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || d ) -> ( -. 2 || d /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 81 | 66 73 75 77 80 | 2rspcedvdw |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || d ) -> E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 82 |  | breq2 |  |-  ( g = e -> ( 2 || g <-> 2 || e ) ) | 
						
							| 83 | 82 | notbid |  |-  ( g = e -> ( -. 2 || g <-> -. 2 || e ) ) | 
						
							| 84 |  | oveq1 |  |-  ( g = e -> ( g gcd h ) = ( e gcd h ) ) | 
						
							| 85 | 84 | eqeq1d |  |-  ( g = e -> ( ( g gcd h ) = 1 <-> ( e gcd h ) = 1 ) ) | 
						
							| 86 |  | oveq1 |  |-  ( g = e -> ( g ^ 4 ) = ( e ^ 4 ) ) | 
						
							| 87 | 86 | oveq1d |  |-  ( g = e -> ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( ( e ^ 4 ) + ( h ^ 4 ) ) ) | 
						
							| 88 | 87 | eqeq1d |  |-  ( g = e -> ( ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) <-> ( ( e ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) | 
						
							| 89 | 85 88 | anbi12d |  |-  ( g = e -> ( ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) <-> ( ( e gcd h ) = 1 /\ ( ( e ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 90 | 83 89 | anbi12d |  |-  ( g = e -> ( ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> ( -. 2 || e /\ ( ( e gcd h ) = 1 /\ ( ( e ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) ) | 
						
							| 91 |  | oveq2 |  |-  ( h = d -> ( e gcd h ) = ( e gcd d ) ) | 
						
							| 92 | 91 | eqeq1d |  |-  ( h = d -> ( ( e gcd h ) = 1 <-> ( e gcd d ) = 1 ) ) | 
						
							| 93 |  | oveq1 |  |-  ( h = d -> ( h ^ 4 ) = ( d ^ 4 ) ) | 
						
							| 94 | 93 | oveq2d |  |-  ( h = d -> ( ( e ^ 4 ) + ( h ^ 4 ) ) = ( ( e ^ 4 ) + ( d ^ 4 ) ) ) | 
						
							| 95 | 94 | eqeq1d |  |-  ( h = d -> ( ( ( e ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) <-> ( ( e ^ 4 ) + ( d ^ 4 ) ) = ( f ^ 2 ) ) ) | 
						
							| 96 | 92 95 | anbi12d |  |-  ( h = d -> ( ( ( e gcd h ) = 1 /\ ( ( e ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) <-> ( ( e gcd d ) = 1 /\ ( ( e ^ 4 ) + ( d ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 97 | 96 | anbi2d |  |-  ( h = d -> ( ( -. 2 || e /\ ( ( e gcd h ) = 1 /\ ( ( e ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> ( -. 2 || e /\ ( ( e gcd d ) = 1 /\ ( ( e ^ 4 ) + ( d ^ 4 ) ) = ( f ^ 2 ) ) ) ) ) | 
						
							| 98 | 76 | ad2antrr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> e e. NN ) | 
						
							| 99 | 74 | ad2antrr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> d e. NN ) | 
						
							| 100 |  | simpr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> -. 2 || e ) | 
						
							| 101 | 98 | nnzd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> e e. ZZ ) | 
						
							| 102 | 99 | nnzd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> d e. ZZ ) | 
						
							| 103 | 101 102 | gcdcomd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( e gcd d ) = ( d gcd e ) ) | 
						
							| 104 |  | simplrl |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( d gcd e ) = 1 ) | 
						
							| 105 | 103 104 | eqtrd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( e gcd d ) = 1 ) | 
						
							| 106 |  | 4nn0 |  |-  4 e. NN0 | 
						
							| 107 | 106 | a1i |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> 4 e. NN0 ) | 
						
							| 108 | 98 107 | nnexpcld |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( e ^ 4 ) e. NN ) | 
						
							| 109 | 108 | nncnd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( e ^ 4 ) e. CC ) | 
						
							| 110 | 99 107 | nnexpcld |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( d ^ 4 ) e. NN ) | 
						
							| 111 | 110 | nncnd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( d ^ 4 ) e. CC ) | 
						
							| 112 | 109 111 | addcomd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( ( e ^ 4 ) + ( d ^ 4 ) ) = ( ( d ^ 4 ) + ( e ^ 4 ) ) ) | 
						
							| 113 |  | simplrr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) | 
						
							| 114 | 112 113 | eqtrd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( ( e ^ 4 ) + ( d ^ 4 ) ) = ( f ^ 2 ) ) | 
						
							| 115 | 100 105 114 | jca32 |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> ( -. 2 || e /\ ( ( e gcd d ) = 1 /\ ( ( e ^ 4 ) + ( d ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 116 | 90 97 98 99 115 | 2rspcedvdw |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ -. 2 || e ) -> E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 117 | 74 | ad2antrr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> d e. NN ) | 
						
							| 118 | 117 | nnsqcld |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( d ^ 2 ) e. NN ) | 
						
							| 119 | 76 | ad2antrr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> e e. NN ) | 
						
							| 120 | 119 | nnsqcld |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( e ^ 2 ) e. NN ) | 
						
							| 121 |  | simp-4r |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> f e. NN ) | 
						
							| 122 |  | 2z |  |-  2 e. ZZ | 
						
							| 123 |  | simplrl |  |-  ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) -> d e. NN ) | 
						
							| 124 | 123 | nnzd |  |-  ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) -> d e. ZZ ) | 
						
							| 125 |  | 2nn |  |-  2 e. NN | 
						
							| 126 | 125 | a1i |  |-  ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) -> 2 e. NN ) | 
						
							| 127 |  | dvdsexp2im |  |-  ( ( 2 e. ZZ /\ d e. ZZ /\ 2 e. NN ) -> ( 2 || d -> 2 || ( d ^ 2 ) ) ) | 
						
							| 128 | 122 124 126 127 | mp3an2i |  |-  ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) -> ( 2 || d -> 2 || ( d ^ 2 ) ) ) | 
						
							| 129 | 128 | imp |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> 2 || ( d ^ 2 ) ) | 
						
							| 130 |  | 2nn0 |  |-  2 e. NN0 | 
						
							| 131 | 130 | a1i |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> 2 e. NN0 ) | 
						
							| 132 | 117 | nncnd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> d e. CC ) | 
						
							| 133 | 132 | flt4lem |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( d ^ 4 ) = ( ( d ^ 2 ) ^ 2 ) ) | 
						
							| 134 | 119 | nncnd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> e e. CC ) | 
						
							| 135 | 134 | flt4lem |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( e ^ 4 ) = ( ( e ^ 2 ) ^ 2 ) ) | 
						
							| 136 | 133 135 | oveq12d |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( ( ( d ^ 2 ) ^ 2 ) + ( ( e ^ 2 ) ^ 2 ) ) ) | 
						
							| 137 |  | simplrr |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) | 
						
							| 138 | 136 137 | eqtr3d |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( ( ( d ^ 2 ) ^ 2 ) + ( ( e ^ 2 ) ^ 2 ) ) = ( f ^ 2 ) ) | 
						
							| 139 |  | simplrl |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( d gcd e ) = 1 ) | 
						
							| 140 | 125 | a1i |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> 2 e. NN ) | 
						
							| 141 |  | rppwr |  |-  ( ( d e. NN /\ e e. NN /\ 2 e. NN ) -> ( ( d gcd e ) = 1 -> ( ( d ^ 2 ) gcd ( e ^ 2 ) ) = 1 ) ) | 
						
							| 142 | 117 119 140 141 | syl3anc |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( ( d gcd e ) = 1 -> ( ( d ^ 2 ) gcd ( e ^ 2 ) ) = 1 ) ) | 
						
							| 143 | 139 142 | mpd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( ( d ^ 2 ) gcd ( e ^ 2 ) ) = 1 ) | 
						
							| 144 | 118 120 121 131 138 143 | fltaccoprm |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( ( d ^ 2 ) gcd f ) = 1 ) | 
						
							| 145 | 118 120 121 129 144 138 | flt4lem2 |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> -. 2 || ( e ^ 2 ) ) | 
						
							| 146 | 119 | nnzd |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> e e. ZZ ) | 
						
							| 147 |  | dvdsexp2im |  |-  ( ( 2 e. ZZ /\ e e. ZZ /\ 2 e. NN ) -> ( 2 || e -> 2 || ( e ^ 2 ) ) ) | 
						
							| 148 | 122 146 140 147 | mp3an2i |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> ( 2 || e -> 2 || ( e ^ 2 ) ) ) | 
						
							| 149 | 145 148 | mtod |  |-  ( ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) /\ 2 || d ) -> -. 2 || e ) | 
						
							| 150 | 149 | ex |  |-  ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) -> ( 2 || d -> -. 2 || e ) ) | 
						
							| 151 |  | imor |  |-  ( ( 2 || d -> -. 2 || e ) <-> ( -. 2 || d \/ -. 2 || e ) ) | 
						
							| 152 | 150 151 | sylib |  |-  ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) -> ( -. 2 || d \/ -. 2 || e ) ) | 
						
							| 153 | 81 116 152 | mpjaodan |  |-  ( ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) /\ ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) -> E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 154 | 153 | ex |  |-  ( ( ( ph /\ f e. NN ) /\ ( d e. NN /\ e e. NN ) ) -> ( ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) -> E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) ) | 
						
							| 155 | 154 | rexlimdvva |  |-  ( ( ph /\ f e. NN ) -> ( E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) -> E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) ) | 
						
							| 156 | 155 | reximdva |  |-  ( ph -> ( E. f e. NN E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) -> E. f e. NN E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) ) | 
						
							| 157 | 156 | con3d |  |-  ( ph -> ( -. E. f e. NN E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) -> -. E. f e. NN E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 158 |  | ralnex |  |-  ( A. f e. NN -. E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) <-> -. E. f e. NN E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 159 |  | ralnex |  |-  ( A. f e. NN -. E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) <-> -. E. f e. NN E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) | 
						
							| 160 | 157 158 159 | 3imtr4g |  |-  ( ph -> ( A. f e. NN -. E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) -> A. f e. NN -. E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 161 |  | rabeq0 |  |-  ( { f e. NN | E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) } = (/) <-> A. f e. NN -. E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 162 |  | rabeq0 |  |-  ( { f e. NN | E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) } = (/) <-> A. f e. NN -. E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) | 
						
							| 163 | 160 161 162 | 3imtr4g |  |-  ( ph -> ( { f e. NN | E. g e. NN E. h e. NN ( -. 2 || g /\ ( ( g gcd h ) = 1 /\ ( ( g ^ 4 ) + ( h ^ 4 ) ) = ( f ^ 2 ) ) ) } = (/) -> { f e. NN | E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) } = (/) ) ) | 
						
							| 164 | 57 163 | mpd |  |-  ( ph -> { f e. NN | E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) } = (/) ) | 
						
							| 165 |  | oveq1 |  |-  ( f = ( c / ( ( a gcd b ) ^ 2 ) ) -> ( f ^ 2 ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) | 
						
							| 166 | 165 | eqeq2d |  |-  ( f = ( c / ( ( a gcd b ) ^ 2 ) ) -> ( ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) <-> ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) ) | 
						
							| 167 | 166 | anbi2d |  |-  ( f = ( c / ( ( a gcd b ) ^ 2 ) ) -> ( ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) <-> ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) ) ) | 
						
							| 168 |  | oveq1 |  |-  ( d = ( a / ( a gcd b ) ) -> ( d gcd e ) = ( ( a / ( a gcd b ) ) gcd e ) ) | 
						
							| 169 | 168 | eqeq1d |  |-  ( d = ( a / ( a gcd b ) ) -> ( ( d gcd e ) = 1 <-> ( ( a / ( a gcd b ) ) gcd e ) = 1 ) ) | 
						
							| 170 |  | oveq1 |  |-  ( d = ( a / ( a gcd b ) ) -> ( d ^ 4 ) = ( ( a / ( a gcd b ) ) ^ 4 ) ) | 
						
							| 171 | 170 | oveq1d |  |-  ( d = ( a / ( a gcd b ) ) -> ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( e ^ 4 ) ) ) | 
						
							| 172 | 171 | eqeq1d |  |-  ( d = ( a / ( a gcd b ) ) -> ( ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) <-> ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( e ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) ) | 
						
							| 173 | 169 172 | anbi12d |  |-  ( d = ( a / ( a gcd b ) ) -> ( ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) <-> ( ( ( a / ( a gcd b ) ) gcd e ) = 1 /\ ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( e ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) ) ) | 
						
							| 174 |  | oveq2 |  |-  ( e = ( b / ( a gcd b ) ) -> ( ( a / ( a gcd b ) ) gcd e ) = ( ( a / ( a gcd b ) ) gcd ( b / ( a gcd b ) ) ) ) | 
						
							| 175 | 174 | eqeq1d |  |-  ( e = ( b / ( a gcd b ) ) -> ( ( ( a / ( a gcd b ) ) gcd e ) = 1 <-> ( ( a / ( a gcd b ) ) gcd ( b / ( a gcd b ) ) ) = 1 ) ) | 
						
							| 176 |  | oveq1 |  |-  ( e = ( b / ( a gcd b ) ) -> ( e ^ 4 ) = ( ( b / ( a gcd b ) ) ^ 4 ) ) | 
						
							| 177 | 176 | oveq2d |  |-  ( e = ( b / ( a gcd b ) ) -> ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( e ^ 4 ) ) = ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( ( b / ( a gcd b ) ) ^ 4 ) ) ) | 
						
							| 178 | 177 | eqeq1d |  |-  ( e = ( b / ( a gcd b ) ) -> ( ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( e ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) <-> ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( ( b / ( a gcd b ) ) ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) ) | 
						
							| 179 | 175 178 | anbi12d |  |-  ( e = ( b / ( a gcd b ) ) -> ( ( ( ( a / ( a gcd b ) ) gcd e ) = 1 /\ ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( e ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) <-> ( ( ( a / ( a gcd b ) ) gcd ( b / ( a gcd b ) ) ) = 1 /\ ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( ( b / ( a gcd b ) ) ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) ) ) | 
						
							| 180 |  | simplrr |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> a e. NN ) | 
						
							| 181 |  | simprl |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> b e. NN ) | 
						
							| 182 |  | simplrl |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> c e. NN ) | 
						
							| 183 |  | simprr |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) | 
						
							| 184 | 180 181 182 183 | flt4lem6 |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( ( ( a / ( a gcd b ) ) e. NN /\ ( b / ( a gcd b ) ) e. NN /\ ( c / ( ( a gcd b ) ^ 2 ) ) e. NN ) /\ ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( ( b / ( a gcd b ) ) ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) ) | 
						
							| 185 | 184 | simpld |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( ( a / ( a gcd b ) ) e. NN /\ ( b / ( a gcd b ) ) e. NN /\ ( c / ( ( a gcd b ) ^ 2 ) ) e. NN ) ) | 
						
							| 186 | 185 | simp3d |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( c / ( ( a gcd b ) ^ 2 ) ) e. NN ) | 
						
							| 187 | 185 | simp1d |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( a / ( a gcd b ) ) e. NN ) | 
						
							| 188 | 185 | simp2d |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( b / ( a gcd b ) ) e. NN ) | 
						
							| 189 | 180 | nnzd |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> a e. ZZ ) | 
						
							| 190 | 181 | nnzd |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> b e. ZZ ) | 
						
							| 191 | 181 | nnne0d |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> b =/= 0 ) | 
						
							| 192 |  | divgcdcoprm0 |  |-  ( ( a e. ZZ /\ b e. ZZ /\ b =/= 0 ) -> ( ( a / ( a gcd b ) ) gcd ( b / ( a gcd b ) ) ) = 1 ) | 
						
							| 193 | 189 190 191 192 | syl3anc |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( ( a / ( a gcd b ) ) gcd ( b / ( a gcd b ) ) ) = 1 ) | 
						
							| 194 | 184 | simprd |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( ( b / ( a gcd b ) ) ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) | 
						
							| 195 | 193 194 | jca |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> ( ( ( a / ( a gcd b ) ) gcd ( b / ( a gcd b ) ) ) = 1 /\ ( ( ( a / ( a gcd b ) ) ^ 4 ) + ( ( b / ( a gcd b ) ) ^ 4 ) ) = ( ( c / ( ( a gcd b ) ^ 2 ) ) ^ 2 ) ) ) | 
						
							| 196 | 167 173 179 186 187 188 195 | 3rspcedvdw |  |-  ( ( ( ph /\ ( c e. NN /\ a e. NN ) ) /\ ( b e. NN /\ ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) -> E. f e. NN E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) | 
						
							| 197 | 196 | rexlimdvaa |  |-  ( ( ph /\ ( c e. NN /\ a e. NN ) ) -> ( E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) -> E. f e. NN E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 198 | 197 | rexlimdvva |  |-  ( ph -> ( E. c e. NN E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) -> E. f e. NN E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) ) ) | 
						
							| 199 | 198 | con3d |  |-  ( ph -> ( -. E. f e. NN E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) -> -. E. c e. NN E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) | 
						
							| 200 |  | ralnex |  |-  ( A. c e. NN -. E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) <-> -. E. c e. NN E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) | 
						
							| 201 | 199 159 200 | 3imtr4g |  |-  ( ph -> ( A. f e. NN -. E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) -> A. c e. NN -. E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) ) | 
						
							| 202 |  | rabeq0 |  |-  ( { c e. NN | E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) } = (/) <-> A. c e. NN -. E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) ) | 
						
							| 203 | 201 162 202 | 3imtr4g |  |-  ( ph -> ( { f e. NN | E. d e. NN E. e e. NN ( ( d gcd e ) = 1 /\ ( ( d ^ 4 ) + ( e ^ 4 ) ) = ( f ^ 2 ) ) } = (/) -> { c e. NN | E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) } = (/) ) ) | 
						
							| 204 | 164 203 | mpd |  |-  ( ph -> { c e. NN | E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) } = (/) ) | 
						
							| 205 |  | sseq0 |  |-  ( ( { c e. NN | ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) } C_ { c e. NN | E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) } /\ { c e. NN | E. a e. NN E. b e. NN ( ( a ^ 4 ) + ( b ^ 4 ) ) = ( c ^ 2 ) } = (/) ) -> { c e. NN | ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) } = (/) ) | 
						
							| 206 | 15 204 205 | syl2anc |  |-  ( ph -> { c e. NN | ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) } = (/) ) | 
						
							| 207 |  | rabeq0 |  |-  ( { c e. NN | ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) } = (/) <-> A. c e. NN -. ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) ) | 
						
							| 208 | 206 207 | sylib |  |-  ( ph -> A. c e. NN -. ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) ) | 
						
							| 209 |  | oveq1 |  |-  ( c = C -> ( c ^ 2 ) = ( C ^ 2 ) ) | 
						
							| 210 | 209 | eqeq2d |  |-  ( c = C -> ( ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) <-> ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( C ^ 2 ) ) ) | 
						
							| 211 | 210 | necon3bbid |  |-  ( c = C -> ( -. ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) <-> ( ( A ^ 4 ) + ( B ^ 4 ) ) =/= ( C ^ 2 ) ) ) | 
						
							| 212 | 211 | rspcv |  |-  ( C e. NN -> ( A. c e. NN -. ( ( A ^ 4 ) + ( B ^ 4 ) ) = ( c ^ 2 ) -> ( ( A ^ 4 ) + ( B ^ 4 ) ) =/= ( C ^ 2 ) ) ) | 
						
							| 213 | 3 208 212 | sylc |  |-  ( ph -> ( ( A ^ 4 ) + ( B ^ 4 ) ) =/= ( C ^ 2 ) ) |