resistor(power,n1).
resistor(power,n2).

transistor(n2,ground,n1).
transistor(n3,n4,n2).
transistor(n5,ground,n4).


/*
inverter(Input,Output) :-
	Output is the inversion of Input.
*/
inverter(Input,Output) :-
	transistor(Input,ground,Output),
	resistor(power,Output).

/*
nand_gate(Input1,Input2,Output):-
   Output is the logical nand of Input1 and Input2.
*/

nand_gate(Input1,Input2,Output) :-
	transistor(Input1,X,Output),
	transistor(Input2,ground,X),
	resistor(power,Output).

/*
and_gate(Input1,Input2,Output):-
  Output is the logical and of Input1 and Input2.		     
*/

and_gate(Input1,Input2,Output) :-
	nand_gate(Input1,Input2,X),
	inverter(X,Output).

%Program 2.2: A circuit for a logical and-gate