System Feature
	conversion

Purpose
	Rules for coverting one data type to another

Syntax
	These type conversions are performed automatically.
	There is no explicit syntax.

Description
	When variables and constants of various types are intermixed in expressions,
	all types are converted to the type of highest operability.
	The following list shows the operability order.

	real	<----------- Highest operability
	int
	string
	bool	<----------- Lowest operability

	The following chart shows how the automatic conversion is performed.

	From			To
	------	------------------------------------------------------------------------------------------------------------------------------
		real	int	string	bool
		---------------	---------------	---------------	---------------
	real	-	Not applicable	Not applicable	Not applicable
	
	int	.0 is added to	-	Not applicable	Not applicable
		value

	string	0.0 if string is	0 if string is	-	Not applicable
		empty, else	empty, else 1
		1.0

	bool	0.0 if false,	0 if false,	"0.0" if false,	-
		else 1.0	else 1	else "1.0"	
		
Restrictions
	The above chart representations automatic conversions that are performed
	during evaluation of an expression that contains intermixed types.

	For conversions that are represented as 'Not applicable' in the above
	chart, automatic conversion is not possible. These conversions must be
	made explicitly using one of the make functions - see help page on make.

Valid Examples
	var int i
	var real x
	set $i=5
	set $x=10.0
	if ($i < $x)
		...
	$i will be converted to real during comparison.


Invalid Examples
	var int i
	var real x
	if ( ( $x ) AND ( $i < 7 ) )
		...
	Will produce an error, since operator AND operates only on type bool.
	variable x is not of type bool, but of type real. Operator AND can not operate
	on data type real, and an automatic conversion is not possible from type real
	to type bool.

See Also
var
constant
make
makebool
makestr
makeint
makereal