Cover
Chapter I
Chapter II
Chapter III
Chapter IV
Maple Package

# Introduction to Shalosh B. Ekhad's

# "120 Pix-A-Pix Problems"

By Doron Zeilberger

Written: Feb. 17, 2009.

## The Rules

You have to reconstruct a "picture" on the given grid, with the given information.
The information lists the lenghts of consecutive runs of black squares in each row and
column. Of course there must be at least one white space between any consecutive runs
of black squares, but there does not have to be a white space at the very beginning or
at the very end (but it may, of course).
To get an idea, simply look at the
first problem and its
solution.

## The Maple package

In order to use
the Maple package PICAPIX,
just download it, and follow the on-line
instructions. Have fun!
Of course, you need to have the computer algebra system
Maple on your computer.

Cover
Chapter I
Chapter II
Chapter III
Chapter IV
Maple Package