Answer to user "G36"
I did in correspond with your example. It work, but as NOR gate. Becauce, I have follow truth table in Proteus (where logical 1 = 5V and 0 = 1V):
a | 1V 1V 5V 5V
b | 1V 5V 1V 5V
--+-------------------
y | 5V 0V 0V 0V
See screenshots further.



