code: public static boolean in(double x, double min, double max) {
          return in(x, min, max, true, true);
      }
docs: Indicates whether `x` is within the closed boundaries
  
  @param x is the value
  @param min is the minimum of the range
  @param max is the maximum of the range
  @return ` \begin{cases} x \in [\min,\max] & \mbox{if $geq \wedge leq$}
  \cr x \in (\min,\max] & \mbox{if $geq \wedge \bar{leq}$} \cr x \in [\min,
  \max) & \mbox{if $\bar{geq} \wedge leq$} \cr x \in (\min, \max) & \mbox{if
  $\bar{geq} \wedge \bar{leq}$} \cr \end{cases}
  `