\[\left(x \cdot x + \left(x \cdot 2\right) \cdot y\right) + y \cdot y\]

\left(x \cdot x + \left(x \cdot 2\right) \cdot y\right) + y \cdot y

double f(double x, double y) {
        double r9112 = x;
        double r9113 = r9112 * r9112;
        double r9114 = 2.0;
        double r9115 = r9112 * r9114;
        double r9116 = y;
        double r9117 = r9115 * r9116;
        double r9118 = r9113 + r9117;
        double r9119 = r9116 * r9116;
        double r9120 = r9118 + r9119;
        return r9120;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019179 
(FPCore (x y)
  :name "Examples.Basics.ProofTests:f4 from sbv-4.4"

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

  (+ (+ (* x x) (* (* x 2.0) y)) (* y y)))

Backtrace

result arity mismatch; expected number of values not received expected: 2 received: 1 in: local-binding form values...: 0		L	C
loop	/data/pavpan/nightlies/herbie/various-cleanup/src/core/extraction.rkt	25	2
(unnamed)	/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt	26	0
simplify!	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	217	0
run-improve43	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	339	0
(unnamed)	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.0/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.0/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	261	28