[sdiy] Simple "theremin" schematic question

[Pat Kammerer]

Hello all,

I finally got a part I needed to throw this together, and then realized I
was one step short of understanding the schemtaic.
http://www.maxiespages.com/images/Theremin/simple.jpg

What I need to know is what the plus in a circle is at pin one of both 4093
chips.  Is this supply voltage, and used for a reference?  Or is this
something else?

Also I noticed that there is not mention of pins 4,10, and 11... anyone know
if I should do anything with those?

Hypothetically, If I were to make this from HCT or LS TTL chips instead,
would I run all of the unused inputs to the supply voltage instead of
ground?  Would I need a resistor?

Thanks in advance!
Pat