Frames add intelligence the data representation

derive d=4. The backward chaining system starts with the goal of finding a value for d and uses the two rules to reduce that to the problem of finding values for a and b.

Forward Chaining

Data		Rules
a=1	IF a=1 & b=2 THEN C=3 IF C=3 THEN d=4			d=4
b=2

Subgoals		Rules		Goal
a=1	IF a=1 & b=2 THEN C=3 IF C=3 THEN d=4
b=2

Frames
mammal

Figure 1.3 Four levels of data representation

In a furniture placement system each piece of furniture can inherit default values for length. When the piece is placed, demons are activated which automatically adjust the available space where the item was placed.

User Interface