% starting point
start _ x = 1;
start _ y = 1;
% step size
step _ x =- 1;
step _ y = 1;
Percentage of points to be calculated
num _ point = 5;
% produce arithmetic progression.
point _ x = start _ x:step _ x:start _ x+(num _ point- 1)* step _ x;
point _ y = start _ y:step _ y:start _ y+(num _ point- 1)* step _ y;
% display value
Display (point x)
Display (point y)
% drawing
Drawing (x point, y point)