Solution for your first question:

1. Create your interested class by right clicking in the 'Class Hierarchy' window and select 'Insert class'. Give the name and select color as you want.
2. Double click on Contained >> and(min). The 'Insert expression' dialog will open.
3. Double click on feature you supposed to give a value; for example Object features >>> Layer values >>> Mean >>> NIR. The 'Membership function' window will open. ![enter image description here][1]
4. Initialize the fuzzy diagram; in your case, select the last one which covers the minimum to maximum and give the values in the box given. ![enter image description here][2]![enter image description here][3]
5. Do the same from the first step for the creation of second class.
6. Instead 'Assign class' algorithm, use 'Classification' algorithm. Select class1 and class2 in the 'Active classes' field. Execute the process. ![enter image description here][4]

This is for your second question

1. Do the same from step one to step four; again double click on and(min) to define the next variable.

You can define different feature values to define a class. There is no limit. Even you can give thresholds by clicking 'Thresholds' in the 'Insert Expression' dialog box.

Regards, Sandhya [1]: https://i.sstatic.net/F0Pak.jpg [2]: https://i.sstatic.net/wMqk4.jpg [3]: https://i.sstatic.net/Ch21r.jpg [4]: https://i.sstatic.net/WMUdn.jpg

Solution for your first question:

1. Create your interested class by right clicking in the 'Class Hierarchy' window and select 'Insert class'. Give the name and select color as you want.
2. Double click on Contained >> and(min). The 'Insert expression' dialog will open.
3. Double click on feature you supposed to give a value; for example Object features >>> Layer values >>> Mean >>> NIR. The 'Membership function' window will open.
4. Initialize the fuzzy diagram; in your case, select the last one which covers the minimum to maximum and give the values in the box given.
5. Do the same from the first step for the creation of second class.
6. Instead 'Assign class' algorithm, use 'Classification' algorithm. Select class1 and class2 in the 'Active classes' field. Execute the process.

This is for your second question

1. Do the same from step one to step four; again double click on and(min) to define the next variable.

You can define different feature values to define a class. There is no limit. Even you can give thresholds by clicking 'Thresholds' in the 'Insert Expression' dialog box.

Regards, Sandhya