Average Error: 29.0 → 22.2
Time: 27.7s
Precision: 64
Internal Precision: 128
\[{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}\]
\[\begin{array}{l} \mathbf{if}\;n \le -964894.1011799229 \lor \neg \left(n \le 7.586550074092197\right):\\ \;\;\;\;\left(\frac{1}{x \cdot n} + \frac{\frac{\frac{-1}{2}}{x}}{x \cdot n}\right) + \frac{\log x}{\left(x \cdot n\right) \cdot n}\\ \mathbf{else}:\\ \;\;\;\;\sqrt[3]{\log \left(\sqrt{e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right) + \log \left(\sqrt{e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)} \cdot \log \left(e^{\sqrt[3]{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)\\ \end{array}\]

Error

Bits error versus x

Bits error versus n

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 2 regimes
  2. if n < -964894.1011799229 or 7.586550074092197 < n

    1. Initial program 44.5

      \[{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}\]
    2. Using strategy rm
    3. Applied add-log-exp44.5

      \[\leadsto {\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - \color{blue}{\log \left(e^{{x}^{\left(\frac{1}{n}\right)}}\right)}\]
    4. Applied add-log-exp44.5

      \[\leadsto \color{blue}{\log \left(e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)}}\right)} - \log \left(e^{{x}^{\left(\frac{1}{n}\right)}}\right)\]
    5. Applied diff-log44.5

      \[\leadsto \color{blue}{\log \left(\frac{e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)}}}{e^{{x}^{\left(\frac{1}{n}\right)}}}\right)}\]
    6. Simplified44.5

      \[\leadsto \log \color{blue}{\left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}\right)}\]
    7. Taylor expanded around inf 32.7

      \[\leadsto \color{blue}{\frac{1}{x \cdot n} - \left(\frac{\log \left(\frac{1}{x}\right)}{x \cdot {n}^{2}} + \frac{1}{2} \cdot \frac{1}{{x}^{2} \cdot n}\right)}\]
    8. Simplified32.7

      \[\leadsto \color{blue}{\frac{\log x}{n \cdot \left(n \cdot x\right)} + \left(\frac{\frac{\frac{-1}{2}}{x}}{n \cdot x} + \frac{1}{n \cdot x}\right)}\]

    if -964894.1011799229 < n < 7.586550074092197

    1. Initial program 7.7

      \[{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}\]
    2. Using strategy rm
    3. Applied add-log-exp7.9

      \[\leadsto {\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - \color{blue}{\log \left(e^{{x}^{\left(\frac{1}{n}\right)}}\right)}\]
    4. Applied add-log-exp7.8

      \[\leadsto \color{blue}{\log \left(e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)}}\right)} - \log \left(e^{{x}^{\left(\frac{1}{n}\right)}}\right)\]
    5. Applied diff-log7.8

      \[\leadsto \color{blue}{\log \left(\frac{e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)}}}{e^{{x}^{\left(\frac{1}{n}\right)}}}\right)}\]
    6. Simplified7.8

      \[\leadsto \log \color{blue}{\left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}\right)}\]
    7. Using strategy rm
    8. Applied add-cube-cbrt7.8

      \[\leadsto \log \left(e^{\color{blue}{\left(\sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}\right) \cdot \sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}}\right)\]
    9. Applied exp-prod7.8

      \[\leadsto \log \color{blue}{\left({\left(e^{\sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)}^{\left(\sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}\right)}\right)}\]
    10. Applied log-pow7.8

      \[\leadsto \color{blue}{\sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \log \left(e^{\sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)}\]
    11. Using strategy rm
    12. Applied add-log-exp7.8

      \[\leadsto \sqrt[3]{\color{blue}{\log \left(e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}\right)}} \cdot \log \left(e^{\sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)\]
    13. Using strategy rm
    14. Applied add-sqr-sqrt7.8

      \[\leadsto \sqrt[3]{\log \color{blue}{\left(\sqrt{e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}} \cdot \sqrt{e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)}} \cdot \log \left(e^{\sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)\]
    15. Applied log-prod7.8

      \[\leadsto \sqrt[3]{\color{blue}{\log \left(\sqrt{e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right) + \log \left(\sqrt{e^{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)}} \cdot \log \left(e^{\sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(1 + x\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)\]
  3. Recombined 2 regimes into one program.
  4. Final simplification22.2

    \[\leadsto \begin{array}{l} \mathbf{if}\;n \le -964894.1011799229 \lor \neg \left(n \le 7.586550074092197\right):\\ \;\;\;\;\left(\frac{1}{x \cdot n} + \frac{\frac{\frac{-1}{2}}{x}}{x \cdot n}\right) + \frac{\log x}{\left(x \cdot n\right) \cdot n}\\ \mathbf{else}:\\ \;\;\;\;\sqrt[3]{\log \left(\sqrt{e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right) + \log \left(\sqrt{e^{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)} \cdot \log \left(e^{\sqrt[3]{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}} \cdot \sqrt[3]{{\left(x + 1\right)}^{\left(\frac{1}{n}\right)} - {x}^{\left(\frac{1}{n}\right)}}}\right)\\ \end{array}\]

Reproduce

herbie shell --seed 2019022 
(FPCore (x n)
  :name "2nthrt (problem 3.4.6)"
  (- (pow (+ x 1) (/ 1 n)) (pow x (/ 1 n))))

Details

Time bar (total: 26.6s)Debug log

sample329.0ms

Algorithm
intervals
Results
96.0ms93×body1280valid
50.0ms28×body640nan
46.0ms54×body640valid
34.0ms41×body10240exit
22.0ms146×body80valid
16.0ms14×body1280nan
16.0ms134×body80nan
15.0ms26×body320valid
7.0ms14×body160valid
7.0ms13×body320nan
2.0msbody160nan

simplify6.0ms

Counts
1 → 1
Calls
1 calls:
Slowest
6.0ms
(- (pow (+ x 1) (/ 1 n)) (pow x (/ 1 n)))

prune6.0ms

Pruning

1 alts after pruning (1 fresh and 0 done)

Merged error: 32.4b

localize31.0ms

Local error

Found 3 expressions with local error:

2.4b
(- (pow (+ x 1) (/ 1 n)) (pow x (/ 1 n)))
1.0b
(pow x (/ 1 n))
0.8b
(pow (+ x 1) (/ 1 n))

rewrite19.0ms

Algorithm
rewrite-expression-head
Rules
10×add-sqr-sqrt
*-un-lft-identity
pow-unpow
add-cube-cbrt
add-log-exp
add-exp-log
unpow-prod-down
pow1
add-cbrt-cube
difference-of-squares
div-inv
pow-to-exp
distribute-lft-out--
flip--
pow-exp
diff-log
flip3--
pow-pow
sub-neg
Counts
3 → 44
Calls
3 calls:
Slowest
14.0ms
(- (pow (+ x 1) (/ 1 n)) (pow x (/ 1 n)))
3.0ms
(pow (+ x 1) (/ 1 n))
1.0ms
(pow x (/ 1 n))

series348.0ms

Counts
3 → 9
Calls
3 calls:
Slowest
215.0ms
(- (pow (+ x 1) (/ 1 n)) (pow x (/ 1 n)))
81.0ms
(pow (+ x 1) (/ 1 n))
51.0ms
(pow x (/ 1 n))

simplify1.4s

Counts
28 → 53
Calls
28 calls:
Slowest
504.0ms
(- (+ (/ (log -1) n) (+ 1 (/ 1 (* x n)))) (/ (log (/ -1 x)) n))
260.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))
246.0ms
(- (/ 1 (* x n)) (+ (/ (log (/ 1 x)) (* x (pow n 2))) (* 1/2 (/ 1 (* (pow x 2) n)))))
199.0ms
(- (+ (* 1/2 (/ (pow (log (/ 1 x)) 2) (pow n 2))) 1) (/ (log (/ 1 x)) n))
61.0ms
(- (+ (/ (log -1) n) (+ (* 1/2 (/ (pow (log -1) 2) (pow n 2))) (+ (* 1/2 (/ (pow (log (/ -1 x)) 2) (pow n 2))) 1))) (+ (/ (log (/ -1 x)) n) (/ (* (log (/ -1 x)) (log -1)) (pow n 2))))

prune528.0ms

Pruning

5 alts after pruning (5 fresh and 0 done)

Merged error: 22.2b

localize15.0ms

Local error

Found 4 expressions with local error:

2.4b
(log (exp (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))
2.4b
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
1.0b
(pow x (/ 1 n))
0.8b
(pow (+ 1 x) (/ 1 n))

rewrite28.0ms

Algorithm
rewrite-expression-head
Rules
17×add-sqr-sqrt
13×*-un-lft-identity
add-cube-cbrt
pow-unpow
log-pow
add-log-exp
exp-prod
pow1
add-exp-log
unpow-prod-down
log-prod
difference-of-squares
add-cbrt-cube
distribute-lft-out--
div-inv
exp-sum
sub-neg
pow-to-exp
flip--
pow-exp
rem-log-exp
diff-log
exp-diff
flip3--
pow-pow
log-div
Counts
4 → 65
Calls
4 calls:
Slowest
17.0ms
(log (exp (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))
8.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
1.0ms
(pow (+ 1 x) (/ 1 n))
1.0ms
(pow x (/ 1 n))

series531.0ms

Counts
4 → 12
Calls
4 calls:
Slowest
204.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
193.0ms
(log (exp (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))
71.0ms
(pow (+ 1 x) (/ 1 n))
63.0ms
(pow x (/ 1 n))

simplify2.3s

Counts
44 → 77
Calls
44 calls:
Slowest
552.0ms
(- (+ (/ (log -1) n) (+ 1 (/ 1 (* x n)))) (/ (log (/ -1 x)) n))
308.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))
304.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))
271.0ms
(- (/ 1 (* x n)) (+ (/ (log (/ 1 x)) (* x (pow n 2))) (* 1/2 (/ 1 (* (pow x 2) n)))))
224.0ms
(- (+ (* 1/2 (/ (pow (log (/ 1 x)) 2) (pow n 2))) 1) (/ (log (/ 1 x)) n))

prune885.0ms

Pruning

7 alts after pruning (7 fresh and 0 done)

Merged error: 22.2b

localize17.0ms

Local error

Found 4 expressions with local error:

2.4b
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
2.4b
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
2.4b
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
1.9b
(log (exp (* (cbrt (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))) (cbrt (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))))

rewrite35.0ms

Algorithm
rewrite-expression-head
Rules
17×add-sqr-sqrt
11×add-log-exp
11×*-un-lft-identity
difference-of-squares
add-cube-cbrt
pow1
add-exp-log
add-cbrt-cube
distribute-lft-out--
flip--
log-pow
diff-log
flip3--
unpow-prod-down
sub-neg
log-prod
rem-log-exp
exp-to-pow
exp-prod
Counts
4 → 59
Calls
4 calls:
Slowest
14.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
10.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
8.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
2.0ms
(log (exp (* (cbrt (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))) (cbrt (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))))

series1.1s

Counts
4 → 12
Calls
4 calls:
Slowest
495.0ms
(log (exp (* (cbrt (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))) (cbrt (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))))
208.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
189.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
174.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))

simplify2.3s

Counts
36 → 71
Calls
36 calls:
Slowest
274.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))
266.0ms
(- (/ 1 (* x n)) (+ (/ (log (/ 1 x)) (* x (pow n 2))) (* 1/2 (/ 1 (* (pow x 2) n)))))
263.0ms
(- (+ (* 2/3 (/ (* (exp (* 1/3 (+ (* 2 (log (/ -1 x))) (* 2 (log (/ -1 n)))))) (log -1)) n)) (exp (* 1/3 (+ (* 2 (log (/ -1 x))) (* 2 (log (/ -1 n))))))) (+ (* 2/3 (/ (* (log (/ -1 x)) (exp (* 1/3 (+ (* 2 (log (/ -1 x))) (* 2 (log (/ -1 n))))))) n)) (* 1/3 (/ (exp (* 1/3 (+ (* 2 (log (/ -1 x))) (* 2 (log (/ -1 n)))))) x))))
260.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))
246.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))

prune936.0ms

Pruning

7 alts after pruning (7 fresh and 0 done)

Merged error: 22.2b

localize14.0ms

Local error

Found 4 expressions with local error:

2.4b
(log (exp (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))
2.4b
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
2.4b
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
2.4b
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))

rewrite58.0ms

Algorithm
rewrite-expression-head
Rules
22×add-sqr-sqrt
14×*-un-lft-identity
10×add-log-exp
difference-of-squares
log-pow
add-cube-cbrt
exp-prod
log-prod
pow1
distribute-lft-out--
add-exp-log
add-cbrt-cube
unpow-prod-down
sub-neg
flip--
diff-log
flip3--
exp-sum
rem-log-exp
exp-diff
log-div
Counts
4 → 66
Calls
4 calls:
Slowest
23.0ms
(log (exp (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))
16.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
9.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
8.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))

series846.0ms

Counts
4 → 12
Calls
4 calls:
Slowest
233.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
217.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))
213.0ms
(log (exp (- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))))
182.0ms
(- (pow (+ 1 x) (/ 1 n)) (pow x (/ 1 n)))

simplify2.4s

Counts
43 → 78
Calls
43 calls:
Slowest
313.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))
285.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))
285.0ms
(- (/ 1 (* x n)) (+ (/ (log (/ 1 x)) (* x (pow n 2))) (* 1/2 (/ 1 (* (pow x 2) n)))))
250.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))
235.0ms
(- (+ (/ (log -1) (* x (pow n 2))) (/ 1 (* x n))) (+ (* 1/2 (/ 1 (* (pow x 2) n))) (/ (log (/ -1 x)) (* x (pow n 2)))))

prune1.2s

Pruning

7 alts after pruning (7 fresh and 0 done)

Merged error: 22.2b

regimes254.0ms

Accuracy

82.9% (1.4b remaining)

Error of 22.2b against oracle of 20.8b and baseline of 29.0b

bsearch429.0ms

end0.0ms

sample10.6s

Algorithm
intervals
Results
3.6s3133×body1280valid
1.3s1134×body10240exit
1.3s1543×body640valid
1.2s4787×body80valid
742.0ms640×body1280nan
599.0ms5030×body80nan
537.0ms661×body640nan
511.0ms831×body320valid
253.0ms377×body320nan
153.0ms473×body160valid
102.0ms166×body160nan