Jmat.Real.erfi, branch x less than or equal to 0.5

Specification

?
\[x \leq 0.5\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\left|x\right| \cdot \left|x\right|\right) \cdot \left|x\right|\\ t_1 := \left(t\_0 \cdot \left|x\right|\right) \cdot \left|x\right|\\ \left|\frac{1}{\sqrt{\mathsf{PI}\left(\right)}} \cdot \left(\left(\left(2 \cdot \left|x\right| + \frac{2}{3} \cdot t\_0\right) + \frac{1}{5} \cdot t\_1\right) + \frac{1}{21} \cdot \left(\left(t\_1 \cdot \left|x\right|\right) \cdot \left|x\right|\right)\right)\right| \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* (* (fabs x) (fabs x)) (fabs x)))
        (t_1 (* (* t_0 (fabs x)) (fabs x))))
   (fabs
    (*
     (/ 1.0 (sqrt (PI)))
     (+
      (+ (+ (* 2.0 (fabs x)) (* (/ 2.0 3.0) t_0)) (* (/ 1.0 5.0) t_1))
      (* (/ 1.0 21.0) (* (* t_1 (fabs x)) (fabs x))))))))
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\left|x\right| \cdot \left|x\right|\right) \cdot \left|x\right|\\
t_1 := \left(t\_0 \cdot \left|x\right|\right) \cdot \left|x\right|\\
\left|\frac{1}{\sqrt{\mathsf{PI}\left(\right)}} \cdot \left(\left(\left(2 \cdot \left|x\right| + \frac{2}{3} \cdot t\_0\right) + \frac{1}{5} \cdot t\_1\right) + \frac{1}{21} \cdot \left(\left(t\_1 \cdot \left|x\right|\right) \cdot \left|x\right|\right)\right)\right|
\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024346 
(FPCore (x)
  :name "Jmat.Real.erfi, branch x less than or equal to 0.5"
  :precision binary64
  :pre (<= x 0.5)
  (fabs (* (/ 1.0 (sqrt (PI))) (+ (+ (+ (* 2.0 (fabs x)) (* (/ 2.0 3.0) (* (* (fabs x) (fabs x)) (fabs x)))) (* (/ 1.0 5.0) (* (* (* (* (fabs x) (fabs x)) (fabs x)) (fabs x)) (fabs x)))) (* (/ 1.0 21.0) (* (* (* (* (* (* (fabs x) (fabs x)) (fabs x)) (fabs x)) (fabs x)) (fabs x)) (fabs x)))))))

Please file a bug report with this information.

Backtrace

>: contract violation expected: real? given: '#s(logfloat 4.0 0.0 #t 2.0 0.0)LC
predict-errors-eftsan/home/nightlies/herbie/bhargav-eftsan/src/core/explain.rkt350
explain!/home/nightlies/herbie/bhargav-eftsan/src/core/mainloop.rkt3210
run-improve!/home/nightlies/herbie/bhargav-eftsan/src/core/mainloop.rkt460
get-alternatives/report/home/nightlies/herbie/bhargav-eftsan/src/api/sandbox.rkt1860
(unnamed)/home/nightlies/herbie/bhargav-eftsan/src/api/sandbox.rkt2826
(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