PLOGHELP PLOGSHOWTREE                             J L Cunningham, Nov 82
                                Revised by Kathryn Seifert  October 1986

Library package for drawing out a tree representing a list

Keywords: list, graphical display


See the POP-11 file HELP * SHOWTREE for a more complete explanation of
the facilities provided by LIB SHOWTREE.

Almost everything written in HELP * SHOWTREE applies when calling
SHOWTREE from Prolog, although of course you have to use Prolog syntax.
The following is a list of the predicates that are available:

To load the library package:

    ?- library(showtree).

Type the following to have List drawn out as a tree:

    ?- showtree(List).

The following is the same as the predicate 'showtree', except that a
useful message for non-Ved users is printed above the resulting diagram:

    ?- showtreemess(Tree).

The predicate 'vgap' can be used either to find out the amount of space
which will be placed between parent and daughter nodes in the tree, or
to set this value:

    ?- vgap(X).         /* find value of vgap */
    ?- vgap(6).         /* set value of vgap */

The predicate 'tree_printable' can be used to make the displayed tree
printable on most line printers:

    ?- tree_printable.

The predicate 'tree_graphical' will make showtree use the characters
used before 'tree_printable' was called:

    ?- tree_graphical.

-- RELATED DOCUMENTATION ----------------------------------------------

HELP * SHOWTREE
 POP-11 HELP file giving details on LIB SHOWTREE

PLOGHELP * SHOWTERM
 Library package for displaying a tree representing a term

PLOGHELP * PARSEDEMO
 Library demonstration program of a simple natural language parser,
 using LIB * SHOWTREE.