Me again.
Looking at the examples, now I'm messing with Chirp.
I cannot understand what Tinc and Inc are. I think that tinc is something like the time of every step from a freq to another one, is it right? 
And Inc is how much freq increases according to tinc's time, is it correct?

But what is -count-? A counter of what? And  what " while ( count < steps ) " and " 1+ => count " mean?

http://chuck.cs.princeton.edu/doc/examples/basic/chirp.ck

thanks!