Exception for Hyperbolic tangent

Specification

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \frac{e^{x} - t\_0}{e^{x} + t\_0} \end{array} \end{array} \]

(FPCore (x)
 :precision binary64
 (let* ((t_0 (exp (- x)))) (/ (- (exp x) t_0) (+ (exp x) t_0))))

double code(double x) {
	double t_0 = exp(-x);
	return (exp(x) - t_0) / (exp(x) + t_0);
}

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = exp(-x)
    code = (exp(x) - t_0) / (exp(x) + t_0)
end function

public static double code(double x) {
	double t_0 = Math.exp(-x);
	return (Math.exp(x) - t_0) / (Math.exp(x) + t_0);
}

def code(x):
	t_0 = math.exp(-x)
	return (math.exp(x) - t_0) / (math.exp(x) + t_0)

function code(x)
	t_0 = exp(Float64(-x))
	return Float64(Float64(exp(x) - t_0) / Float64(exp(x) + t_0))
end

function tmp = code(x)
	t_0 = exp(-x);
	tmp = (exp(x) - t_0) / (exp(x) + t_0);
end

code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, N[(N[(N[Exp[x], $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]

\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{-x}\\
\frac{e^{x} - t\_0}{e^{x} + t\_0}
\end{array}
\end{array}

Reproduce

herbie shell --seed 2024170 
(FPCore (x)
  :name "Hyperbolic tangent"
  :precision binary64
  (/ (- (exp x) (exp (- x))) (+ (exp x) (exp (- x)))))

Please file a bug report with this information.

Backtrace

timeline-push!: contract violation expected: jsexpr? given: '#hash((#t . 0.2498779296875) (unknown . 0.7496337890625) (precondition . 0.00048828125) (valid . 0.0)) in: the repeated argument of (-> symbol? jsexpr? ... void?) contract from: <pkgs>/herbie/timeline.rkt blaming: <pkgs>/herbie/searchreals.rkt (assuming the contract is correct) at: <pkgs>/herbie/timeline.rkt:10:3		L	C
raise-blame-error	/usr/local/racket/collects/racket/contract/private/blame.rkt	346	0
loop	/usr/local/racket/collects/racket/contract/private/list.rkt	991	12
(unnamed)	.../private/arrow-val-first.rkt	486	18
find-intervals	/home/nightlies/herbie/zane-job-abstraction3/src/searchreals.rkt	86	0
make-sampler	/home/nightlies/herbie/zane-job-abstraction3/src/sampling.rkt	110	0
sample-points	/home/nightlies/herbie/zane-job-abstraction3/src/sampling.rkt	244	0
setup-context!	/home/nightlies/herbie/zane-job-abstraction3/src/mainloop.rkt	45	0
get-alternatives/report	/home/nightlies/herbie/zane-job-abstraction3/src/sandbox.rkt	166	0
(unnamed)	/home/nightlies/herbie/zane-job-abstraction3/src/sandbox.rkt	260	6
(unnamed)	/usr/local/racket/share/pkgs/profile-lib/main.rkt	40	10
profile-thunk	/usr/local/racket/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/usr/local/racket/collects/racket/engine.rkt	42	24