Polarity being parsed but not showing up in trees

[robclouth]

This pizza isn't warm is parsed successfully, but the resulting tree is just:
Is ( This ( Pizza ) ) Warm

The negation is ignored. How do I get the polarity to be put into the tree? I expect something like:

Not( Is ( This ( Pizza ) ) Warm)

I'm using the RGL.

[robclouth]

I figured it out. Polarity only comes into play at the S level, not Cl level.