Problem 5 Propositions

Intro:  Representation is still a problem.  We cannot store more than
clear or obstacle in our current system.  In addition we are restricted in
our representation to 2d search type problems.  We want to eventually be
able to reason about more general problems, so we will try to switch to a
more general representation.  For continuity we will still apply it to the
same problem.  Two more bits of information will now be applicable to each
block.

Given:  Same as problem 2.

Problem:  Create a representation that can hold three facts about each
block:  obstacle (yes or no), high (yes or no), and stable (yes or no).
The second two are only applicable when the block is an object.  This
added info in the representation gives us more options for reasoning.  
Come up with a scheme that can do reasoning without the grid for storage.  
We are not so concerned with the efficiency at this point and will not even
be using the heuristic.  We just want to find a representation that can be 
used to find if there is a path to the goal.  

After we have a way to list facts we need a way to reason with these
facts.  Such as if the block is clear (not an obstacle) we can step into
it or if it is an obstacle that is not high and stable we can step on to
it.  Determine how to add rules that will allow you to reason about the
facts developed above.  Give examples of these rules.