8.5 #unless

The template:

#set $count = 9
#unless $count + 5 > 15
Count is in range.
#end unless

The output:

Count is in range.

The generated code:

        count = 9
        if not (count + 5 > 15):
            write('Count is in range.\n')

Note: There is a bug in Cheetah 0.9.13. It's forgetting the parentheses in the if expression, which could lead to it calculating something different than it should.