Logistic regression 2

Specification

?
\[\begin{array}{l} \\ \log \left(1 + e^{x}\right) - x \cdot y \end{array} \]
(FPCore (x y) :precision binary64 (- (log (+ 1.0 (exp x))) (* x y)))
double code(double x, double y) {
	return log((1.0 + exp(x))) - (x * y);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = log((1.0d0 + exp(x))) - (x * y)
end function
public static double code(double x, double y) {
	return Math.log((1.0 + Math.exp(x))) - (x * y);
}
def code(x, y):
	return math.log((1.0 + math.exp(x))) - (x * y)
function code(x, y)
	return Float64(log(Float64(1.0 + exp(x))) - Float64(x * y))
end
function tmp = code(x, y)
	tmp = log((1.0 + exp(x))) - (x * y);
end
code[x_, y_] := N[(N[Log[N[(1.0 + N[Exp[x], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\log \left(1 + e^{x}\right) - x \cdot y
\end{array}

Reproduce

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herbie shell --seed 2023271 
(FPCore (x y)
  :name "Logistic regression 2"
  :precision binary64

  :herbie-target
  (if (<= x 0.0) (- (log (+ 1.0 (exp x))) (* x y)) (- (log (+ 1.0 (exp (- x)))) (* (- x) (- 1.0 y))))

  (- (log (+ 1.0 (exp x))) (* x y)))

Please file a bug report with this information.

Backtrace

length: contract violation expected: list? given: 8000LC
(unnamed)/home/nightlies/herbie/arb-support/egg-herbie/main.rkt1112
egraph-run/home/nightlies/herbie/main/src/core/egg-herbie.rkt5020
egraph-run-rules/home/nightlies/herbie/main/src/core/egg-herbie.rkt5590
run-egg/home/nightlies/herbie/main/src/core/egg-herbie.rkt2880
simplify-batch/home/nightlies/herbie/main/src/core/simplify.rkt150
(unnamed)/usr/share/racket/collects/racket/contract/private/arrow-higher-order.rkt37933
find-preprocessing/home/nightlies/herbie/main/src/preprocess.rkt110
run-improve!/home/nightlies/herbie/main/src/mainloop.rkt3250
get-alternatives/report/home/nightlies/herbie/main/src/sandbox.rkt1490
(unnamed)/home/nightlies/herbie/main/src/sandbox.rkt2456
(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