In this section the parameters for various component properties are set. As the pressure is low enough ideal conditions will be assumed. SYSOP0 is the property method in Aspen Plus™ that provides ideal behavior in liquid and vapor phases. You can get information about a feature by selecting the What�s this?� entry from Help menu and clicking on the feature you are interested in. Most of the time a yellow tool tip box will pop up with a short reasonable description.