| Step | Hyp | Ref | Expression | 
						
							| 1 |  | quart.a |  |-  ( ph -> A e. CC ) | 
						
							| 2 |  | quart.b |  |-  ( ph -> B e. CC ) | 
						
							| 3 |  | quart.c |  |-  ( ph -> C e. CC ) | 
						
							| 4 |  | quart.d |  |-  ( ph -> D e. CC ) | 
						
							| 5 |  | quart.x |  |-  ( ph -> X e. CC ) | 
						
							| 6 |  | quart.e |  |-  ( ph -> E = -u ( A / 4 ) ) | 
						
							| 7 |  | quart.p |  |-  ( ph -> P = ( B - ( ( 3 / 8 ) x. ( A ^ 2 ) ) ) ) | 
						
							| 8 |  | quart.q |  |-  ( ph -> Q = ( ( C - ( ( A x. B ) / 2 ) ) + ( ( A ^ 3 ) / 8 ) ) ) | 
						
							| 9 |  | quart.r |  |-  ( ph -> R = ( ( D - ( ( C x. A ) / 4 ) ) + ( ( ( ( A ^ 2 ) x. B ) / ; 1 6 ) - ( ( 3 / ; ; 2 5 6 ) x. ( A ^ 4 ) ) ) ) ) | 
						
							| 10 |  | quart.u |  |-  ( ph -> U = ( ( P ^ 2 ) + ( ; 1 2 x. R ) ) ) | 
						
							| 11 |  | quart.v |  |-  ( ph -> V = ( ( -u ( 2 x. ( P ^ 3 ) ) - ( ; 2 7 x. ( Q ^ 2 ) ) ) + ( ; 7 2 x. ( P x. R ) ) ) ) | 
						
							| 12 |  | quart.w |  |-  ( ph -> W = ( sqrt ` ( ( V ^ 2 ) - ( 4 x. ( U ^ 3 ) ) ) ) ) | 
						
							| 13 | 1 2 3 4 7 8 9 | quart1cl |  |-  ( ph -> ( P e. CC /\ Q e. CC /\ R e. CC ) ) | 
						
							| 14 | 13 | simp1d |  |-  ( ph -> P e. CC ) | 
						
							| 15 | 14 | sqcld |  |-  ( ph -> ( P ^ 2 ) e. CC ) | 
						
							| 16 |  | 1nn0 |  |-  1 e. NN0 | 
						
							| 17 |  | 2nn |  |-  2 e. NN | 
						
							| 18 | 16 17 | decnncl |  |-  ; 1 2 e. NN | 
						
							| 19 | 18 | nncni |  |-  ; 1 2 e. CC | 
						
							| 20 | 13 | simp3d |  |-  ( ph -> R e. CC ) | 
						
							| 21 |  | mulcl |  |-  ( ( ; 1 2 e. CC /\ R e. CC ) -> ( ; 1 2 x. R ) e. CC ) | 
						
							| 22 | 19 20 21 | sylancr |  |-  ( ph -> ( ; 1 2 x. R ) e. CC ) | 
						
							| 23 | 15 22 | addcld |  |-  ( ph -> ( ( P ^ 2 ) + ( ; 1 2 x. R ) ) e. CC ) | 
						
							| 24 | 10 23 | eqeltrd |  |-  ( ph -> U e. CC ) | 
						
							| 25 |  | 2cn |  |-  2 e. CC | 
						
							| 26 |  | 3nn0 |  |-  3 e. NN0 | 
						
							| 27 |  | expcl |  |-  ( ( P e. CC /\ 3 e. NN0 ) -> ( P ^ 3 ) e. CC ) | 
						
							| 28 | 14 26 27 | sylancl |  |-  ( ph -> ( P ^ 3 ) e. CC ) | 
						
							| 29 |  | mulcl |  |-  ( ( 2 e. CC /\ ( P ^ 3 ) e. CC ) -> ( 2 x. ( P ^ 3 ) ) e. CC ) | 
						
							| 30 | 25 28 29 | sylancr |  |-  ( ph -> ( 2 x. ( P ^ 3 ) ) e. CC ) | 
						
							| 31 | 30 | negcld |  |-  ( ph -> -u ( 2 x. ( P ^ 3 ) ) e. CC ) | 
						
							| 32 |  | 2nn0 |  |-  2 e. NN0 | 
						
							| 33 |  | 7nn |  |-  7 e. NN | 
						
							| 34 | 32 33 | decnncl |  |-  ; 2 7 e. NN | 
						
							| 35 | 34 | nncni |  |-  ; 2 7 e. CC | 
						
							| 36 | 13 | simp2d |  |-  ( ph -> Q e. CC ) | 
						
							| 37 | 36 | sqcld |  |-  ( ph -> ( Q ^ 2 ) e. CC ) | 
						
							| 38 |  | mulcl |  |-  ( ( ; 2 7 e. CC /\ ( Q ^ 2 ) e. CC ) -> ( ; 2 7 x. ( Q ^ 2 ) ) e. CC ) | 
						
							| 39 | 35 37 38 | sylancr |  |-  ( ph -> ( ; 2 7 x. ( Q ^ 2 ) ) e. CC ) | 
						
							| 40 | 31 39 | subcld |  |-  ( ph -> ( -u ( 2 x. ( P ^ 3 ) ) - ( ; 2 7 x. ( Q ^ 2 ) ) ) e. CC ) | 
						
							| 41 |  | 7nn0 |  |-  7 e. NN0 | 
						
							| 42 | 41 17 | decnncl |  |-  ; 7 2 e. NN | 
						
							| 43 | 42 | nncni |  |-  ; 7 2 e. CC | 
						
							| 44 | 14 20 | mulcld |  |-  ( ph -> ( P x. R ) e. CC ) | 
						
							| 45 |  | mulcl |  |-  ( ( ; 7 2 e. CC /\ ( P x. R ) e. CC ) -> ( ; 7 2 x. ( P x. R ) ) e. CC ) | 
						
							| 46 | 43 44 45 | sylancr |  |-  ( ph -> ( ; 7 2 x. ( P x. R ) ) e. CC ) | 
						
							| 47 | 40 46 | addcld |  |-  ( ph -> ( ( -u ( 2 x. ( P ^ 3 ) ) - ( ; 2 7 x. ( Q ^ 2 ) ) ) + ( ; 7 2 x. ( P x. R ) ) ) e. CC ) | 
						
							| 48 | 11 47 | eqeltrd |  |-  ( ph -> V e. CC ) | 
						
							| 49 | 48 | sqcld |  |-  ( ph -> ( V ^ 2 ) e. CC ) | 
						
							| 50 |  | 4cn |  |-  4 e. CC | 
						
							| 51 |  | expcl |  |-  ( ( U e. CC /\ 3 e. NN0 ) -> ( U ^ 3 ) e. CC ) | 
						
							| 52 | 24 26 51 | sylancl |  |-  ( ph -> ( U ^ 3 ) e. CC ) | 
						
							| 53 |  | mulcl |  |-  ( ( 4 e. CC /\ ( U ^ 3 ) e. CC ) -> ( 4 x. ( U ^ 3 ) ) e. CC ) | 
						
							| 54 | 50 52 53 | sylancr |  |-  ( ph -> ( 4 x. ( U ^ 3 ) ) e. CC ) | 
						
							| 55 | 49 54 | subcld |  |-  ( ph -> ( ( V ^ 2 ) - ( 4 x. ( U ^ 3 ) ) ) e. CC ) | 
						
							| 56 | 55 | sqrtcld |  |-  ( ph -> ( sqrt ` ( ( V ^ 2 ) - ( 4 x. ( U ^ 3 ) ) ) ) e. CC ) | 
						
							| 57 | 12 56 | eqeltrd |  |-  ( ph -> W e. CC ) | 
						
							| 58 | 24 48 57 | 3jca |  |-  ( ph -> ( U e. CC /\ V e. CC /\ W e. CC ) ) |