We love S-expressions.

The define statement:

(define <name> <value>)
Define will be used to define species, rules, instruction and keep them 
in the database 

To create an instruction:
(instruction <direction> <species>)

To create a predicate:
(predicate <predicate-tree>)

To create a rule:
(rule <predicate> <instruction>)

To create a species:
(species <string-representation> <color> <list of rules>)

You will probably want to define rules blah blah. 
If you try to refer to an uninitialized variable, the database will throw an error.

Here is a simple example:

(define MyPred (DIRECTION NW BLUE))
(define MyInstruction (instruction C RED))
(define MyRule (rule MyPred MyInstruction))
(define MySpecies (species MySpecies GREEN MyRule))


We should probably figure out what directions and colors and blah actually look like.