Hi vinnie
The circuit you have drawn does this:
y=(A and C) or (A and B) or C
which simplifies to this:
y=(A and B) or C
reducing the circuit to one two input and gate and one two input or gate.
(or, xor, nand, xnand...)
xnand? No such thing. Maybe you meant xnor.
If you are looking for circuit simulation, I noticed qucs.tcz in the repository. It appears to support
both analog and digital simulation.