Operators
 + X2 Y2 LINETO
 + X Y R THETA1 THETA2 ARC
 + SETLINEWIDTH ... Set Line Width
 + SETDASH ... Drawing Dotted Line / Broken Line
 + IMAGE ... Drawing Bitmap Images
+

Operators -- CAD
 +  Visible/Hidden/Centre Line

 +  X1 Y1 X2 Y2 RECTANGLE
 +  X Y L SQUARE
 +  X Y R CIRCLE
 + -- CYLINDER
 + -- DISC

 +  X Y THETA DEPTH DT ... Drilled through hole
 +  X Y THETA DEPTH TH-M3 ... Threaded hole for M3 screws
 +  X Y THETA DEPTH SF-M3 ... Spot-facing (SF) holes for M3 cap screws

Examples -- Math
 + SIN
 + COS
 + Parametric :: Asteroid
 + Polar :: Folium

Examples -- Structural Formula
 + BENZENE