#curve  a line on a graph representing data
  supertype:  line.shape  a length (straight or curved) without breadth or thickness; the trace of a moving point
  subtype:  regression_line  a smooth curve fitted to the set of paired data in regression analysis; for linear regression the curve is a straight line
  part of:  graph__graphical_record__graphicalrecord  a drawing illustrating the relations between certain quantities plotted with reference to a set of axes

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