\[\frac{1}{2} \cdot \left(x + y\right)\]
\frac{1}{2} \cdot \left(x + y\right)
(FPCore (x y) :precision binary64 (* (/ 1.0 2.0) (+ x y)))
double code(double x, double y) {
	return ((double) ((1.0 / 2.0) * ((double) (x + y))));
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020203 
(FPCore (x y)
  :name "Diagrams.Solve.Polynomial:cubForm  from diagrams-solve-0.1, G"
  :precision binary64

  :herbie-target
  (/ (+ x y) 2.0)

  (* (/ 1.0 2.0) (+ x y)))

Backtrace

first: contract violation expected: (and/c list? (not/c empty?)) given: '()LC
batch-eval-progs/data/pavpan/nightlies/herbie/cleanup/src/programs.rkt1070
batch-errors/data/pavpan/nightlies/herbie/cleanup/src/points.rkt1690
atab-add-altns/data/pavpan/nightlies/herbie/cleanup/src/core/alt-table.rkt1940
(unnamed)/opt/racket-7.5/collects/racket/contract/private/arrow-val-first.rkt48618
finalize-iter!/data/pavpan/nightlies/herbie/cleanup/src/mainloop.rkt2730
run-iter!/data/pavpan/nightlies/herbie/cleanup/src/mainloop.rkt3410
for-loop/data/pavpan/nightlies/herbie/cleanup/src/mainloop.rkt3794
run-improve41/data/pavpan/nightlies/herbie/cleanup/src/mainloop.rkt3600
.../more-scheme.rkt:261:28unknown
run/opt/racket-7.5/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.5/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.5/collects/racket/private/more-scheme.rkt26128

Reproduce

herbie shell --seed 2020203 
(FPCore (x y)
  :name "Diagrams.Solve.Polynomial:cubForm  from diagrams-solve-0.1, G"
  :precision binary64

  :herbie-target
  (/ (+ x y) 2.0)

  (* (/ 1.0 2.0) (+ x y)))