\[2 \cdot \left(\left(1 \cdot \frac{1}{9} + \frac{1}{9} \cdot \frac{1}{9}\right) + \frac{1}{9} \cdot 1\right)\]
2 \cdot \left(\left(1 \cdot \frac{1}{9} + \frac{1}{9} \cdot \frac{1}{9}\right) + \frac{1}{9} \cdot 1\right)
double f() {
        double r8256 = 2.0;
        double r8257 = 1.0;
        double r8258 = 9.0;
        double r8259 = r8257 / r8258;
        double r8260 = r8257 * r8259;
        double r8261 = r8259 * r8259;
        double r8262 = r8260 + r8261;
        double r8263 = r8259 * r8257;
        double r8264 = r8262 + r8263;
        double r8265 = r8256 * r8264;
        return r8265;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019194 
(FPCore ()
  :name "Rectangular parallelepiped of dimension a×b×c"

  :herbie-target
  (+ (+ (* (* (/ 1.0 9.0) 1.0) 2.0) (* 2.0 (* (/ 1.0 9.0) (/ 1.0 9.0)))) (* 2.0 (* 1.0 (/ 1.0 9.0))))

  (* 2.0 (+ (+ (* 1.0 (/ 1.0 9.0)) (* (/ 1.0 9.0) (/ 1.0 9.0))) (* (/ 1.0 9.0) 1.0))))

Backtrace

car: contract violation expected: pair? given: '()LC
loop/data/pavpan/nightlies/herbie/various-cleanup/src/points.rkt1224
prepare-points/data/pavpan/nightlies/herbie/various-cleanup/src/points.rkt1460
run-improve47/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt3420
(unnamed)/opt/racket-7.0/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.0/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.0/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.0/collects/racket/private/more-scheme.rkt26128