code: def glb(self, other):
          
          return self.__class__(
              [
                  min(self.lower, other.lower),
                  min(self.upper, other.upper)
              ],
              lower_inc=self.lower_inc if self < other else other.lower_inc,
              upper_inc=self.upper_inc if self > other else other.upper_inc,
          )
docs: Return the greatest lower bound for given intervals.
  
          :param other: AbstractInterval instance