Plotl uses a stack oriented math command syntax. Each math command is surrounded by braces, {}. For exmaple {2 5 add} would push the number 2 onto the stack, push the number 5 on the stack, the command add would add them together, resulting in 7.

Any valid operand, number, or variable can be placed in a math command. Also, math commands can either affect data, (i.e., x={x x mul}) or be used as input on plotl commands (i.e., xmin { pi 2 div }).

Nested math commands are not allowed. That is, anything that looks like {{something}} is invalid.