\[\tan^{-1} \left(N + 1\right) - \tan^{-1} N \]
(FPCore (N) :precision binary64 (- (atan (+ N 1.0)) (atan N)))
double code(double N) {
	return atan((N + 1.0)) - atan(N);
}
real(8) function code(n)
    real(8), intent (in) :: n
    code = atan((n + 1.0d0)) - atan(n)
end function
public static double code(double N) {
	return Math.atan((N + 1.0)) - Math.atan(N);
}
def code(N):
	return math.atan((N + 1.0)) - math.atan(N)
function code(N)
	return Float64(atan(Float64(N + 1.0)) - atan(N))
end
function tmp = code(N)
	tmp = atan((N + 1.0)) - atan(N);
end
code[N_] := N[(N[ArcTan[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[ArcTan[N], $MachinePrecision]), $MachinePrecision]
\tan^{-1} \left(N + 1\right) - \tan^{-1} N

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2022349 
(FPCore (N)
  :name "2atan (example 3.5)"
  :precision binary64

  :herbie-target
  (atan (/ 1.0 (+ 1.0 (* N (+ N 1.0)))))

  (- (atan (+ N 1.0)) (atan N)))

Backtrace

error writing to stream port system error: Broken pipe; errno=32LC
writeln/usr/share/racket/collects/racket/private/misc.rkt1564
run-egglog/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/egglog/run-egglog.rkt13010
run-simplify-input/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/core/simplify.rkt740
simplify-batch/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/core/simplify.rkt510
(unnamed)/usr/share/racket/collects/racket/contract/private/arrow-higher-order.rkt37933
get-swaps/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/symmetry.rkt60
connected-components/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/symmetry.rkt200
run-improve!/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/mainloop.rkt3200
(unnamed)/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/sandbox.rkt556
(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