Notation

In most cases, FlexPDE notation is simple text as in a programming language.

•	Differentiation, such as du/dx, is denoted by the form dx(u). All active coordinate names are recognized, as are second derivatives like dxx(u) and differential operators Div, Grad and Curl.

•	Names are NOT case sensitive. "F" is the same as "f".

•	Comments can be placed liberally in the text. Use { } to enclose comments or ! to ignore the remainder of the line.

Note: See the Problem Descriptor Reference chapter on Elements for a full description of FlexPDE notation.