The lines are 0.7mm

The drawing on the picture is for showing the actual motion. But the programmed motion is only a line.

Circles (on the drawing) are at the true positions. But after g1 z..., every motion g1 x... or g1 y... or g1 x..y.. motions are like 0.2mm to right w.r.t direction of the motion and line and at the end 0.2mm left (back to the true position).

For example:

Initial position x=0,y=0,z=0

g1 z-15 => x=0,y=0,z-15

g1 x20 =>x=0,y=0.2,z-15 and x20,y=0.2,z-15 and x=20,y=0,z=-15

g1 y20 =>x=20.2,y=0,z-15 and x=20.2,y=20,z-15 and x=20,y=20,z=-15

g1 x0 y0 => x=19.9,y=20.1,z-15 and x=-0.1,y=0.1,z=-15 and x=0,y=0,z=-15

There is no tool offset, there is no G41,G42 command.