ERROR:

	When an error occurs during an RLaB session, it can be classed
	as one of two types. Either a parse error, or a run-time
	error. We will discuss both below.

	All error messages attempt to provide both file and line
	number information to help locate the error; unless the error
	occurs at the command line.

	Parse errors:

	A parse error is an error that occurs while RLaB is converting
	an expression to it's compiled form. Each statement that is
	typed at the command line prompt, or read from a file, is
	compiled, and then executed. If the error occurs during this
	conversion, the error message is predicated with the string
	"parse error". 

	The line number information is exact when parse errors
	occur. However, the token identified as the offender may not
	be the problem. In many instance it is difficult for the
	parser to tell what was intended, and it's guess at the
	offending token are not always correct.

	Run-time errors:

	A run-time error is any error that is not a parse error.
	Run-time errors occur during execution of the compiled
	statements. Run time error messages are predicated with the
	name of the executing program; usually "rlab". 

	The line number information is not always exact when run-time
	errors occur. If you cannot find anything wrong with the
	identified line, the look above, or below, one or two lines.
