anchor.diff:  )
   (defun DT:AddLayer ( layerName layerColor layerLineType / layerObject )
     ; Create a new layer and set name, color and linetype.
  -  (if (and layerName layerColor)
  +  (if (and layerName layerColor layerLineType)
       (if
         (and
           (= 'str (type layerName))
  
positive.code:     );END cond
    );END if
  
    ; v0.0 - 2017.03.10 - First issue
    ; Author: David Torralba
    ; Last revision: 2017.03.10
  )
  (defun DT:GetPointList ( msg / p pointList scapeVariable )
    ; Return a list with selected points, nil if none
  
negative.code:       (cond
          ((/= 'str (type layerName))     (princ "\nERROR @ DT:AddLayer : layerName is not a string\n")      (princ) )
          ((/= 'int (type layerColor))    (princ "\nERROR @ DT:AddLayer : layerColor is not an integer\n")   (princ) )
          ((/= 'str (type layerLineType)) (princ "\nERROR @ DT:AddLayer : layerLineType is not a string\n")(princ) )
        );END cond
      );END if
      (cond
  