Tutorial of lib/backtracking
############################

The cluster lib/backtracking provides a useful abstraction to implement
all kinds of backtracking algorithms or and/or tree explorations.

The tutorial backtracking/expand_expression
===========================================

The main class, ABSTRACT_BACKTRACKING,
implements the abstract algorithm that explore a virtual and/or tree.
It defines the basic data used for the explorations and the way the exploration
is done. The tutorial [expand_expression] shows its use.

That tutorial expands the expressions that are entered at its input.
Here is a short example.

{{{{
> cd expand_expression/tree
> se c -clean -o ee expand_expression
> ./ee
the(good+bad)(boy+girl)
        (1)     the good boy
        (2)     the good girl
        (3)     the bad boy
        (4)     the bad girl
}}}}


The tutorial backtracking/logigram
==================================

A tutorial that shows how to solve problems 
that sometimes are called logigrams. The logigrams
are made of a set of items (persons, date, places, ...)
grouped into categories and sets of true propositions 
about the items. From these propositions you must deduce
how the given items are combined together.

Here is an example: there are 3 women, Marie, Julie and Eve of
the 19th century. We know that:
 - The one who has no child was born in 1804 and she is not Marie.
 - Julie doesn't have exactly one child and has less children than Marie.
 - The one who had 2 children was not born in 1805 and she is not Eve.
Which woman is born in 1806? How many children did she have?

The tutorial backtracking/tiny_parse
==============================

WORK IN PROGRESS NOTHING TO SEE HERE

The tutorial backtracking/tiny_prolog
===============================

WORK IN PROGRESS NOTHING TO SEE HERE

Some other examples
===================

The cluster regular_expression uses the cluster bactracking.
Just take a look at it.

.end

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.def ^\.end  <div class="sesign"><rule/>Copyright \&copy; The SmartEiffel Team - <a href="mailto:SmartEiffel@loria.fr">\&lt;SmartEiffel@loria.fr\&gt;</a></div>