how to patch various types of wave modulations

[x.iso]

Does anyone have tips on how to make same type of wave manipulations as described in following video?
https://www.youtube.com/watch?v=6HaLnRl1xvs
There's a schematic, but it's made for analogue oscillators and physical device. Couldn't quite wrap my head around what kind of manipulations he did in terms of math (well, I'm not good at math).

[oli_lab]

multiplying with a number from 1 to -1 ?

and + and - modules as well

File uploaded: http://www.sensomusic.org/forums/upload ... verter.wkp

[x.iso]

Ok, so basically it really is just sum of two oscillators with different frequencies.