Specification

\[\begin{array}{l} \\ \tanh^{-1} x \end{array} \]

(FPCore (x) :precision binary64 (atanh x))

double code(double x) {
	return atanh(x);
}

def code(x):
	return math.atanh(x)

function code(x)
	return atanh(x)
end

function tmp = code(x)
	tmp = atanh(x);
end

code[x_] := N[ArcTanh[x], $MachinePrecision]

\begin{array}{l}

\\
\tanh^{-1} x
\end{array}

Reproduce

herbie shell --seed 2023189 
(FPCore (x)
  :name "Rust f64::atanh"
  :precision binary64
  (* 0.5 (log1p (/ (* 2.0 x) (- 1.0 x)))))

Please file a bug report with this information.

application: not a procedure; expected a procedure that can be applied to arguments given: '(0 . #<procedure:f>)		L	C
taylor-log	/home/nightlies/herbie/preprocess-initial-simplify/src/core/taylor.rkt	486	0
taylor*	/home/nightlies/herbie/preprocess-initial-simplify/src/core/taylor.rkt	99	0
hash-ref!	/usr/share/racket/collects/racket/private/more-scheme.rkt	377	2
approximate	/home/nightlies/herbie/preprocess-initial-simplify/src/core/taylor.rkt	7	0
taylor-expr	/home/nightlies/herbie/preprocess-initial-simplify/src/patch.rkt	77	0
taylor-alt	/home/nightlies/herbie/preprocess-initial-simplify/src/patch.rkt	84	0
gen-series!	/home/nightlies/herbie/preprocess-initial-simplify/src/patch.rkt	98	0
patch-table-run	/home/nightlies/herbie/preprocess-initial-simplify/src/patch.rkt	272	0
(unnamed)	/usr/share/racket/collects/racket/contract/private/arrow-val-first.rkt	486	18
run-improve!	/home/nightlies/herbie/preprocess-initial-simplify/src/mainloop.rkt	186	0
get-alternatives/report	/home/nightlies/herbie/preprocess-initial-simplify/src/sandbox.rkt	151	0
(unnamed)	/home/nightlies/herbie/preprocess-initial-simplify/src/sandbox.rkt	250	6
(unnamed)	/usr/share/racket/pkgs/profile-lib/main.rkt	40	10
profile-thunk	/usr/share/racket/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/usr/share/racket/collects/racket/engine.rkt	42	24