Query 20.1: Draw the two dimensional tree which the following L-system produces.
 

axiom: S(4)

Productions:
S(n) -> S(n-1) F : n>1
S(1) -> [+90 F T][-90 F U]
T -> -90 F +45 F B
U-> +90 F -45 F B
B -> [+45 F] [F] [-45 F]

Reminder: + is counterclockwise. The axiom starts out with the turtle headed straight up. F means forward. All other capital letters are just nonterminals in the L-system, and are ignored by the turtle.

Query 20.2: Construct an L-system to produce a weeping willow tree.

Query 20.3: Can you design an L-system that produces some kind of a random tree, but which is left-right symmetric?

Query 20.4: Either locate on the web, or program (in your favorite language) which simulates the Life cellular automaton on a 20 x 20 grid.

Reminder: Life cells have 8 neighbors. A dead cell becomes live if it has three live neighbors. A living cell survives if it has two or three live neighbors. How simple can you get?\

Reminder 2: Automaton is singular. Automata is plural. Automation is none of the above, though they are automated of course. Atomato is a fruit but we think it's a vegetable. Tra la....

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