let b be Nat; :: thesis: for r being real number st ( for n being Nat holds (scf r) . n <= b ) holds
for n being Nat holds (c_d r) . (n + 1) <= ((b + (sqrt ((b ^2 ) + 4))) / 2) |^ (n + 1)
let r be real number ; :: thesis: ( ( for n being Nat holds (scf r) . n <= b ) implies for n being Nat holds (c_d r) . (n + 1) <= ((b + (sqrt ((b ^2 ) + 4))) / 2) |^ (n + 1) )
assume A1:
for n being Nat holds (scf r) . n <= b
; :: thesis: for n being Nat holds (c_d r) . (n + 1) <= ((b + (sqrt ((b ^2 ) + 4))) / 2) |^ (n + 1)
set s = scf r;
set s2 = c_d r;
defpred S2[ Nat] means (c_d r) . ($1 + 1) <= ((b + (sqrt ((b ^2 ) + 4))) / 2) |^ ($1 + 1);
A2:
(c_d r) . (0 + 1) = (scf r) . 1
by Def7;
A3:
(scf r) . 1 <= b
by A1;
(b ^2 ) + 4 > b ^2
by XREAL_1:41;
then
sqrt ((b ^2 ) + 4) > sqrt (b ^2 )
by SQUARE_1:95;
then A4:
sqrt ((b ^2 ) + 4) > b
by SQUARE_1:89;
then
b + (sqrt ((b ^2 ) + 4)) > b + b
by XREAL_1:10;
then
(b + (sqrt ((b ^2 ) + 4))) / 2 > (2 * b) / 2
by XREAL_1:76;
then
((b + (sqrt ((b ^2 ) + 4))) / 2) |^ (0 + 1) > b
by NEWTON:10;
then A5:
S2[ 0 ]
by A2, A3, XXREAL_0:2;
A6: (c_d r) . (1 + 1) =
(((scf r) . (0 + 2)) * ((c_d r) . (0 + 1))) + ((c_d r) . 0 )
by Def7
.=
(((scf r) . 2) * ((c_d r) . 1)) + 1
by Def7
.=
(((scf r) . 2) * ((scf r) . 1)) + 1
by Def7
;
A7:
( (scf r) . 2 >= 0 & (scf r) . 1 >= 0 )
by Th38;
(scf r) . 2 <= b
by A1;
then
((scf r) . 2) * ((scf r) . 1) <= b ^2
by A3, A7, XREAL_1:68;
then A9:
(c_d r) . (1 + 1) <= (b ^2 ) + 1
by A6, XREAL_1:8;
A10: ((b + (sqrt ((b ^2 ) + 4))) / 2) |^ (1 + 1) =
((b + (sqrt ((b ^2 ) + 4))) / 2) ^2
by WSIERP_1:2
.=
(((b ^2 ) + ((2 * b) * (sqrt ((b ^2 ) + 4)))) + ((sqrt ((b ^2 ) + 4)) ^2 )) / (2 * 2)
.=
(((b ^2 ) + ((2 * b) * (sqrt ((b ^2 ) + 4)))) + ((b ^2 ) + 4)) / (2 * 2)
by SQUARE_1:def 4
.=
(((b ^2 ) + (b * (sqrt ((b ^2 ) + 4)))) + 2) / 2
;
b * (sqrt ((b ^2 ) + 4)) >= b * b
by A4, XREAL_1:66;
then
(b ^2 ) + (b * (sqrt ((b ^2 ) + 4))) >= (b ^2 ) + (b * b)
by XREAL_1:8;
then
((b ^2 ) + (b * (sqrt ((b ^2 ) + 4)))) + 2 >= ((b ^2 ) + (b ^2 )) + 2
by XREAL_1:8;
then
(((b ^2 ) + (b * (sqrt ((b ^2 ) + 4)))) + 2) / 2 >= (2 * ((b ^2 ) + 1)) / 2
by XREAL_1:74;
then A11:
S2[1]
by A9, A10, XXREAL_0:2;
A12:
for n being Nat st S2[n] & S2[n + 1] holds
S2[n + 2]
A20:
for n being Nat holds S2[n]
from FIB_NUM:sch 1(A5, A11, A12);
let n be Nat; :: thesis: (c_d r) . (n + 1) <= ((b + (sqrt ((b ^2 ) + 4))) / 2) |^ (n + 1)
thus
(c_d r) . (n + 1) <= ((b + (sqrt ((b ^2 ) + 4))) / 2) |^ (n + 1)
by A20; :: thesis: verum