Exception for 2-ancestry mixing, negative discriminant

Specification

\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]

(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 (PI)) 3.0) (/ (acos (/ (- g) h)) 3.0)))))

\begin{array}{l}

\\
2 \cdot \cos \left(\frac{2 \cdot \mathsf{PI}\left(\right)}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)
\end{array}

Reproduce

herbie shell --seed 2025030 
(FPCore (g h)
  :name "2-ancestry mixing, negative discriminant"
  :precision binary64
  (* 2.0 (cos (+ (/ (* 2.0 (PI)) 3.0) (/ (acos (/ (- g) h)) 3.0)))))

Please file a bug report with this information.

Backtrace

operator-info: Unknown operator binary64		L	C
(unnamed)	/usr/share/racket/collects/racket/contract/private/arrow-higher-order.rkt	379	33
enode-type	/home/nightlies/herbie/really-crazy-encodings/src/core/egg-herbie.rkt	566	0
split-untyped-eclasses	/home/nightlies/herbie/really-crazy-encodings/src/core/egg-herbie.rkt	621	0
make-typed-eclasses	/home/nightlies/herbie/really-crazy-encodings/src/core/egg-herbie.rkt	791	0
make-regraph	/home/nightlies/herbie/really-crazy-encodings/src/core/egg-herbie.rkt	838	0
egraph-best	/home/nightlies/herbie/really-crazy-encodings/src/core/egg-herbie.rkt	1395	0
simplify-batch	/home/nightlies/herbie/really-crazy-encodings/src/core/simplify.rkt	19	0
(unnamed)	/usr/share/racket/collects/racket/contract/private/arrow-val-first.rkt	486	18
initial-simplify	/home/nightlies/herbie/really-crazy-encodings/src/core/preprocess.rkt	54	0
find-preprocessing	/home/nightlies/herbie/really-crazy-encodings/src/core/preprocess.rkt	81	0
run-improve!	/home/nightlies/herbie/really-crazy-encodings/src/core/mainloop.rkt	45	0
get-alternatives/report	/home/nightlies/herbie/really-crazy-encodings/src/api/sandbox.rkt	174	0
(unnamed)	/home/nightlies/herbie/really-crazy-encodings/src/api/sandbox.rkt	265	6
(unnamed)	/usr/share/racket/pkgs/profile-lib/main.rkt	40	10
profile-thunk	/usr/share/racket/pkgs/profile-lib/main.rkt	9	0
in-engine	/home/nightlies/herbie/really-crazy-encodings/src/api/sandbox.rkt	283	2
(unnamed)	/usr/share/racket/collects/racket/engine.rkt	42	24