I published a few months ago a picture of a city rendered using domino tiles
with a macro I wrote en 2002.
Well, if I understand the rules correctly, I can't submit any modified work
done before the contest.

So... Can't I submit any picture using domino tiles as buildings? (the image
was a wip never finished)

As the macro was wrote before the contest, can I use this macro in anyway?

Can't I use any macro,  include or function wrote, before the contest, by me
or others?

So...if I want to obtain a good result: must I rewrite a lightsys.inc (like
Jaime Vives Piqueres (p.e.)) or the Galaxy.inc from Chris Colefax, or must
be considered an illegal action?

As if I could have a chance to win

B. Gimeno