BenLeslie says: Sorry to tell, but sigma0 died!

Well, what can I say, unexpected answer from the kenge users list!. Friendly Ben Leslie answered about sigma1:

Hi Jorge,

We have actually removed the need for sigma1 (and sigma0). On our
latest version it does not exist.

Further e-mail about this I'll write. And about B-toolkit, he was kind enough to CC to the L4 formal method author. And about scheduler I was correct.

Few questions I have for my self, and for Ben off course.