Hi Alex,

went through it.  very interesting. 

quick question.  i could not do ANY of the "key selection" exercises, part c of network 3.

i do not understand it.  never seen anything like it.  the first key selection is a vertical column of stuff.  and then the choices are a horizontal row of stuff.  maybe this is meant to be so, but if not, it is only making it confusing. 

maybe i am just totally blind to something very obvious...

but if you agree that maybe the instructions are not clear enough, do you mind rephrasing them? 

other than that... thanks very much for this work.  it is very pleasantly eye-opening for me. 

cheers,

sirhinojo