LV-muParser provides a simple LabVIEW API for muParser fast math expression parser.
A modified version of muParser v2.2.5 is included. It will be installed to your "<LabVIEW>\resource" directory. I have added support for the "!" (not) operator as well as added ":" as a valid character for variable names.
You will find the muParser API in the functions palette under "Addons > LAVA > muParser"
LV-muParser source on github: https://github.com/rfporter/LV-muParser