#dividing_line__line__demarcation  a conceptual separation or demarcation: "there is a narrow line between sanity and insanity"
  supertype:  differentiation.discrimination__distinction  a discrimination between things as different and distinct; "it is necessary to make a distinction between love and infatuation"
  subtype:  point_of_no_return__Rubicon  a line that when crossed permits of no return and typically results in irrevocable commitment

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