Average Error: 0.3 → 0.3
Time: 4.9s
Precision: 64
Internal Precision: 128
\[\frac{a}{-\cos^{-1} a}\]
\[\frac{a}{-\cos^{-1} a}\]

Error

Bits error versus a

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 0.3

    \[\frac{a}{-\cos^{-1} a}\]
  2. Final simplification0.3

    \[\leadsto \frac{a}{-\cos^{-1} a}\]

Reproduce

herbie shell --seed 2019022 
(FPCore (a)
  :name "Fuzzer 001"
  (/ a (- (acos a))))

Details

Time bar (total: 4.5s)Debug log

sample50.0ms

Algorithm
intervals
Results
23.0ms256×body80valid
15.0ms246×body80nan

simplify2.0ms

Counts
1 → 1
Calls
1 calls:
Slowest
2.0ms
(/ a (- (acos a)))

prune8.0ms

Pruning

1 alts after pruning (1 fresh and 0 done)

Merged error: 0.3b

localize15.0ms

Local error

Found 1 expressions with local error:

0.3b
(/ a (- (acos a)))

rewrite2.0ms

Algorithm
rewrite-expression-head
Rules
10×associate-/r*
add-cube-cbrt
*-un-lft-identity
add-sqr-sqrt
distribute-rgt-neg-in
distribute-lft-neg-in
add-log-exp
div-inv
add-exp-log
add-cbrt-cube
frac-2neg
neg-mul-1
clear-num
pow1
Counts
1 → 20
Calls
1 calls:
Slowest
2.0ms
(/ a (- (acos a)))

series26.0ms

Counts
1 → 3
Calls
1 calls:
Slowest
26.0ms
(/ a (- (acos a)))

simplify70.0ms

Counts
13 → 23
Calls
13 calls:
Slowest
27.0ms
(* -1 (/ a (acos a)))
16.0ms
(* -1 (/ a (acos a)))
15.0ms
(* -1 (/ a (acos a)))
1.0ms
(cbrt (- (acos a)))
1.0ms
(- (sqrt (acos a)))

prune169.0ms

Pruning

7 alts after pruning (6 fresh and 1 done)

Merged error: 0.1b

localize11.0ms

Local error

Found 2 expressions with local error:

0.4b
(* a (/ 1 (- (acos a))))
0.0b
(/ 1 (- (acos a)))

rewrite5.0ms

Algorithm
rewrite-expression-head
Rules
10×associate-/r*
add-cube-cbrt
*-un-lft-identity
add-sqr-sqrt
associate-*r*
add-exp-log
distribute-rgt-neg-in
pow1
distribute-lft-neg-in
add-log-exp
div-inv
add-cbrt-cube
inv-pow
pow-flip
*-commutative
un-div-inv
associate-*r/
frac-2neg
neg-mul-1
clear-num
rec-exp
Counts
2 → 37
Calls
2 calls:
Slowest
3.0ms
(* a (/ 1 (- (acos a))))
2.0ms
(/ 1 (- (acos a)))

series35.0ms

Counts
2 → 6
Calls
2 calls:
Slowest
25.0ms
(* a (/ 1 (- (acos a))))
10.0ms
(/ 1 (- (acos a)))

simplify83.0ms

Counts
23 → 43
Calls
23 calls:
Slowest
15.0ms
(* -1 (/ a (acos a)))
15.0ms
(* -1 (/ a (acos a)))
15.0ms
(* -1 (/ a (acos a)))
4.0ms
(sqrt (/ 1 (- (acos a))))
4.0ms
(cbrt (/ 1 (- (acos a))))

prune272.0ms

Pruning

6 alts after pruning (5 fresh and 1 done)

Merged error: 0.0b

localize5.0ms

Local error

Found 2 expressions with local error:

0.4b
(/ 1 (/ (- (acos a)) a))
0.3b
(/ (- (acos a)) a)

rewrite5.0ms

Algorithm
rewrite-expression-head
Rules
10×associate-/l*
add-cube-cbrt
*-un-lft-identity
add-sqr-sqrt
associate-/r*
div-inv
add-exp-log
distribute-rgt-neg-in
pow1
distribute-lft-neg-in
add-log-exp
add-cbrt-cube
frac-2neg
clear-num
inv-pow
pow-flip
associate-/r/
distribute-frac-neg
div-sub
neg-mul-1
rec-exp
neg-sub0
Counts
2 → 40
Calls
2 calls:
Slowest
3.0ms
(/ (- (acos a)) a)
1.0ms
(/ 1 (/ (- (acos a)) a))

series30.0ms

Counts
2 → 6
Calls
2 calls:
Slowest
15.0ms
(/ 1 (/ (- (acos a)) a))
15.0ms
(/ (- (acos a)) a)

simplify92.0ms

Counts
20 → 46
Calls
20 calls:
Slowest
18.0ms
(* -1 (/ a (acos a)))
15.0ms
(* -1 (/ a (acos a)))
9.0ms
(* -1 (/ a (acos a)))
8.0ms
(* -1 (/ (acos a) a))
7.0ms
(* -1 (/ (acos a) a))

prune320.0ms

Pruning

6 alts after pruning (4 fresh and 2 done)

Merged error: 0.0b

localize11.0ms

Local error

Found 2 expressions with local error:

0.6b
(/ (/ 1 (- (acos a))) (/ 1 a))
0.0b
(/ 1 (- (acos a)))

rewrite11.0ms

Algorithm
rewrite-expression-head
Rules
16×times-frac
15×add-cube-cbrt
15×*-un-lft-identity
15×add-sqr-sqrt
14×associate-/r*
12×div-inv
add-exp-log
associate-/l*
add-cbrt-cube
distribute-rgt-neg-in
pow1
distribute-lft-neg-in
add-log-exp
div-exp
frac-2neg
clear-num
rec-exp
associate-/l/
inv-pow
pow-flip
associate-/r/
neg-mul-1
cbrt-undiv
Counts
2 → 62
Calls
2 calls:
Slowest
7.0ms
(/ (/ 1 (- (acos a))) (/ 1 a))
2.0ms
(/ 1 (- (acos a)))

series32.0ms

Counts
2 → 6
Calls
2 calls:
Slowest
23.0ms
(/ (/ 1 (- (acos a))) (/ 1 a))
9.0ms
(/ 1 (- (acos a)))

simplify1.6s

Counts
58 → 68
Calls
58 calls:
Slowest
909.0ms
(/ (* (* (/ 1 (- (acos a))) (/ 1 (- (acos a)))) (/ 1 (- (acos a)))) (* (* (/ 1 a) (/ 1 a)) (/ 1 a)))
94.0ms
(/ (/ 1 (- (acos a))) (/ 1 a))
62.0ms
(/ (/ 1 (- (acos a))) (/ 1 a))
56.0ms
(/ (/ 1 (- (acos a))) (/ 1 a))
55.0ms
(/ (/ 1 (- (acos a))) (/ 1 a))

prune394.0ms

Pruning

6 alts after pruning (3 fresh and 3 done)

Merged error: 0.0b

regimes67.0ms

Accuracy

0% (0.2b remaining)

Error of 0.3b against oracle of 0.0b and baseline of 0.3b

bsearch1.0ms

end0.0ms

sample1.2s

Algorithm
intervals
Results
612.0ms8000×body80valid
408.0ms7987×body80nan