====== Tree ======
{{tag>trees}}
===== Description =====
Example show how to present data by tree

{{:prolog:pllib:tree.png|}}

**Source**:  PROLOG str. 35 Wydawnictwo PLJ Warszawa 1991 ISBN 83-85190-63-



===== Download =====
Program source code: {{tree.pl}}
===== Listing =====
<code prolog>
ksiazka(autor(wilfrid, hodges), logic, wydanie(penguin,8,1984)).</code>
===== Comments =====