Cannot sample enough valid points. (more)

\[0.0 \lt a \lt b + c \land 0.0 \lt b \lt a + c \land 0.0 \lt c \lt a + b\]
\[\sqrt{\left(\left(\frac{\left(a + b\right) + c}{2} \cdot \left(\frac{\left(a + b\right) + c}{2} - a\right)\right) \cdot \left(\frac{\left(a + b\right) + c}{2} - b\right)\right) \cdot \left(\frac{\left(a + b\right) + c}{2} - c\right)}\]
\sqrt{\left(\left(\frac{\left(a + b\right) + c}{2} \cdot \left(\frac{\left(a + b\right) + c}{2} - a\right)\right) \cdot \left(\frac{\left(a + b\right) + c}{2} - b\right)\right) \cdot \left(\frac{\left(a + b\right) + c}{2} - c\right)}
double code(double a, double b, double c) {
	return ((double) sqrt(((double) (((double) (((double) (((double) (((double) (((double) (a + b)) + c)) / 2.0)) * ((double) (((double) (((double) (((double) (a + b)) + c)) / 2.0)) - a)))) * ((double) (((double) (((double) (((double) (a + b)) + c)) / 2.0)) - b)))) * ((double) (((double) (((double) (((double) (a + b)) + c)) / 2.0)) - c))))));
}

Reproduce

herbie shell --seed 2020150 
(FPCore (a b c)
  :name "Area of a triangle"
  :precision binary64
  :pre (and (< 0.0 a (+ b c)) (< 0.0 b (+ a c)) (< 0.0 c (+ a b)))

  :herbie-target
  (/ (sqrt (* (* (* (+ a (+ b c)) (- c (- a b))) (+ c (- a b))) (+ a (- b c)))) 4.0)

  (sqrt (* (* (* (/ (+ (+ a b) c) 2.0) (- (/ (+ (+ a b) c) 2.0) a)) (- (/ (+ (+ a b) c) 2.0) b)) (- (/ (+ (+ a b) c) 2.0) c))))