Example 1: finding a midpoint (1)
To find the midpoint of a given straight-line segment AB:
1. Draw intersecting circles of equal radius, centered at A and B respectively.2. Let C and D be the points where the circles intersect.3. Draw a straight line between C and D.4. Let E be the point where CD intersects AB.5. Terminate with answer E.
Could be performed by a human equipped with drawing instruments.