SUM
This is part of the function module

Calculate the sum of the arguments

Examples
Glossary of keywords and components
Compulsory keywords
PERIODIC if the output of your function is periodic then you should specify the periodicity of the function. If the output is not periodic you must state this using PERIODIC=NO
Options
ARG the input to this function. You can use multiple instances of this keyword i.e. ARG1, ARG2, ARG3...