EXPRESSION EVALUATOR...     This routine lets you write a mathematical expression, enter numeric values for the expression variables, and have the computer solve it. The program parses the expression into components and performs the operations. The expression evaluator understands the following symbols (upper or lower case entries are OK):

Some general considerations:

NOTE: This routine will only 'catch' errors in the basic numeric expression. It may not detect invalid or meaningless math operations that may be attempted when data are processed, such as division by zero, or taking the log or a non-integer exponent of a negative number. If such situations occur, results may be unpredictable. The algorithm does find most such errors during processing, however.

The underlying code for the expression evaluator was developed by the late, great Robert Purves (recently deceased and greatly missed).  I 'borrowed' it -- with his permission -- and made some modifications for LabHelper.  But Robert P. deserves all the credit.

Other links: