arccos

Specification

?
\[\begin{array}{l} \\ 2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right) \end{array} \]
(FPCore (x) :precision binary64 (* 2.0 (atan (sqrt (/ (- 1.0 x) (+ 1.0 x))))))
double code(double x) {
	return 2.0 * atan(sqrt(((1.0 - x) / (1.0 + x))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0 * atan(sqrt(((1.0d0 - x) / (1.0d0 + x))))
end function
public static double code(double x) {
	return 2.0 * Math.atan(Math.sqrt(((1.0 - x) / (1.0 + x))));
}
def code(x):
	return 2.0 * math.atan(math.sqrt(((1.0 - x) / (1.0 + x))))
function code(x)
	return Float64(2.0 * atan(sqrt(Float64(Float64(1.0 - x) / Float64(1.0 + x)))))
end
function tmp = code(x)
	tmp = 2.0 * atan(sqrt(((1.0 - x) / (1.0 + x))));
end
code[x_] := N[(2.0 * N[ArcTan[N[Sqrt[N[(N[(1.0 - x), $MachinePrecision] / N[(1.0 + x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)
\end{array}

Reproduce

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herbie shell --seed 2024261 
(FPCore (x)
  :name "arccos"
  :precision binary64
  (* 2.0 (atan (sqrt (/ (- 1.0 x) (+ 1.0 x))))))

Please file a bug report with this information.

Backtrace

run-egg: cannot find proof; start and end are not equal. start: #s(approx (- 1 x) (-.f64 #s(literal 1 binary64) x)) end: (fma.f64 #s(literal -2 binary64) x #s(literal 2 binary64))LC
add-soundiness/home/nightlies/herbie/artem-batch-finish-rewrite/src/core/soundiness.rkt1400
extract!/home/nightlies/herbie/artem-batch-finish-rewrite/src/core/mainloop.rkt790
run-improve!/home/nightlies/herbie/artem-batch-finish-rewrite/src/core/mainloop.rkt450
get-alternatives/report/home/nightlies/herbie/artem-batch-finish-rewrite/src/api/sandbox.rkt1860
(unnamed)/home/nightlies/herbie/artem-batch-finish-rewrite/src/api/sandbox.rkt2826
(unnamed)/usr/share/racket/pkgs/profile-lib/main.rkt4010
profile-thunk/usr/share/racket/pkgs/profile-lib/main.rkt90
(unnamed)/usr/share/racket/collects/racket/engine.rkt4224