I am exploring Morphs and I tried the following code:

|sm ws|
    ws := WideString new: 5.
    ws wordAt: 1 put: 16r2264.
    ws wordAt: 2 put: 16r22C5.
    ws wordAt: 3 put: 16r2211.
    ws wordAt: 4 put: 16r2219.
    ws wordAt: 5 put: 16r221A.
    sm := SimpleSwitchMorph new.
    sm label: ws font: (LogicalFont familyName: 'Cambria Math' pointSize: 15).
    sm openInWorld.

Now in the upper left corner of the World screen I have a button that shows the math symbols, LTE, dot, Summation, large-dot and SQRT, and will change backcolor from gray to light-red. Exactly what I wanted; however, how do I get rid of the morph? The class documentation is full of examples of this kind so there must be a way to clean up the World as It persists through a quit and save and then open.

Thanks.