Expression Syntax

The expressions given for the forward and inverse transformations closely follow the syntax of Fortran (with some extensions for compatibility with the C language). They may contain references to variables and literal constants, together with arithmetic, logical, relational and bitwise operators, and function invocations. A set of symbolic constants is also available. Each of these is described in detail below. Parentheses may be used to override the normal order of evaluation. There is no built-in limit to the length of expressions and they are insensitive to case or the presence of additional white space.