Specification

\[\begin{array}{l} \\ \frac{x + y}{x - y} \end{array} \]

(FPCore (x y) :precision binary64 (/ (+ x y) (- x y)))

double code(double x, double y) {
	return (x + y) / (x - y);
}

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

public static double code(double x, double y) {
	return (x + y) / (x - y);
}

def code(x, y):
	return (x + y) / (x - y)

function code(x, y)
	return Float64(Float64(x + y) / Float64(x - y))
end

function tmp = code(x, y)
	tmp = (x + y) / (x - y);
end

code[x_, y_] := N[(N[(x + y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]

\begin{array}{l}

\\
\frac{x + y}{x - y}
\end{array}

Reproduce

herbie shell --seed 2024005 
(FPCore (x y)
  :name "Linear.Projection:perspective from linear-1.19.1.3, A"
  :precision binary64

  :herbie-target
  (/ 1.0 (- (/ x (+ x y)) (/ y (+ x y))))

  (/ (+ x y) (- x y)))

Please file a bug report with this information.

Backtrace

repr->cost: arity mismatch; the expected number of arguments does not match the given number expected: 2 given: 1		L	C
loop	.../private/map.rkt	54	19
f490	.../match/compiler.rkt	548	40
loop	.../private/map.rkt	54	19
f490	.../match/compiler.rkt	548	40
make-alt-table	/home/nightlies/herbie/platforms/src/core/alt-table.rkt	40	0
(unnamed)	/usr/share/racket/collects/racket/contract/private/arrow-val-first.rkt	486	18
initialize-alt-table!	/home/nightlies/herbie/platforms/src/mainloop.rkt	316	0
mutate!	/home/nightlies/herbie/platforms/src/mainloop.rkt	352	0
run-improve!	/home/nightlies/herbie/platforms/src/mainloop.rkt	338	0
get-alternatives/report	/home/nightlies/herbie/platforms/src/sandbox.rkt	169	0
(unnamed)	/home/nightlies/herbie/platforms/src/sandbox.rkt	262	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