Circuit Creation Tutorial

There are two ways to create a circuit. You can either manually specify the circuit or you can load in circuit from a knowledge compiler (currently PySDD and d4 are supported).

Loading Circuits

An SDD can be loaded from a file as follows.

from klay import Circuit

circuit = Circuit()
circuit.add_sdd_from_file("path/to/my.sdd")

Similarly, for d4 we can use

circuit = Circuit()
circuit.add_d4_from_file("path/to/my.nnf")

SDDs can also be loaded directly from a PySDD SddNode object.

from pysdd.sdd import SddManager

manager = SddManager(var_count = 2)
sdd_node = manager.literal(1) & manager.literal(2)

circuit = Circuit()
circuit.add_sdd(sdd_node)

Multi-Rooted Circuits

To evaluate multiple circuits in parallel, you can merge them into a single circuit with multiple roots.

circuit = Circuit()
circuit.add_sdd(first_sdd)
circuit.add_sdd(second_sdd)

Evaluating this circuit will result in an output tensor with two elements. The order in which the circuits are added determines the order of the roots in the output tensor.

Manual Circuits

To create a custom circuit, you can manually define the circuit structure. We start by defining some literal nodes, which are the leafs of the circuit.

circuit = Circuit()
a = circuit.literal_node(1)
b = circuit.literal_node(-2)

Next, create and/or nodes as follows.

and_node = circuit.and_node([a, b])
or_node = circuit.or_node([a, and_node])

You need to set a node as root to indicate that it will be part of the output.

circuit.set_root(or_node)

As we support multi-rooted circuits, you can later add other root nodes.

circuit.set_root(and_node)