Primitive Visual Relations.

This class of symbols describe how certain visual elements relate to each other and miscellaneous slot values.

Visual Relations

1. touching.

2. above-below.

3. right-of-left-of.

4. in-front-of-behind.

5. off-s-image specifies that a part of the element is not visible due to being partially off the image.

Motion Relations

1. rotation has the arguments speed and direction.

2. translation has the arguments speed, direction, and destination.