Falkner and Boettcher, Appendix B, 1

Specification

?
\[\begin{array}{l} \\ \cos^{-1} \left(\frac{1 - 5 \cdot \left(v \cdot v\right)}{v \cdot v - 1}\right) \end{array} \]
(FPCore (v)
 :precision binary64
 (acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))
double code(double v) {
	return acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)));
}
real(8) function code(v)
    real(8), intent (in) :: v
    code = acos(((1.0d0 - (5.0d0 * (v * v))) / ((v * v) - 1.0d0)))
end function
public static double code(double v) {
	return Math.acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)));
}
def code(v):
	return math.acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)))
function code(v)
	return acos(Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(Float64(v * v) - 1.0)))
end
function tmp = code(v)
	tmp = acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)));
end
code[v_] := N[ArcCos[N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(v * v), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\cos^{-1} \left(\frac{1 - 5 \cdot \left(v \cdot v\right)}{v \cdot v - 1}\right)
\end{array}

Reproduce

?
herbie shell --seed 2024248 
(FPCore (v)
  :name "Falkner and Boettcher, Appendix B, 1"
  :precision binary64
  (acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))

Please file a bug report with this information.

Backtrace

error: contract violation expected: string? given: 'acos.f64LC
f374.../match/compiler.rkt55940
loop.../private/map.rkt4019
loop.../private/map.rkt4019
loop.../private/map.rkt4019
loop.../private/map.rkt4019
loop.../private/map.rkt4019
loop.../private/map.rkt4019
loop.../private/map.rkt4019
loop.../private/map.rkt4019
loop.../private/map.rkt4019
compile-expr/home/nightlies/herbie/bhargav-log-space/src/core/explain.rkt700
explain/home/nightlies/herbie/bhargav-log-space/src/core/explain.rkt6130
explain!/home/nightlies/herbie/bhargav-log-space/src/core/mainloop.rkt3220
run-improve!/home/nightlies/herbie/bhargav-log-space/src/core/mainloop.rkt440
get-alternatives/report/home/nightlies/herbie/bhargav-log-space/src/api/sandbox.rkt1860
(unnamed)/home/nightlies/herbie/bhargav-log-space/src/api/sandbox.rkt2826
(unnamed)/usr/local/racket/share/pkgs/profile-lib/main.rkt4010
profile-thunk/usr/local/racket/share/pkgs/profile-lib/main.rkt90
(unnamed)/usr/local/racket/collects/racket/engine.rkt4224