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BooleanExpression

BooleanExpression(expression, name=None)

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Bases: qiskit.circuit.classicalfunction.classical_element.ClassicalElement

The Boolean Expression gate.

Parameters

  • expression (str) – The logical expression string.
  • name (str) – Optional. Instruction gate name. Otherwise part of the expression is going to be used.

Methods

add_decomposition

BooleanExpression.add_decomposition(decomposition)

Add a decomposition of the instruction to the SessionEquivalenceLibrary.

assemble

BooleanExpression.assemble()

Assemble a QasmQobjInstruction

broadcast_arguments

BooleanExpression.broadcast_arguments(qargs, cargs)

Validation and handling of the arguments and its relationship.

For example, cx([q[0],q[1]], q[2]) means cx(q[0], q[2]); cx(q[1], q[2]). This method yields the arguments in the right grouping. In the given example:

in: [[q[0],q[1]], q[2]],[]
outs: [q[0], q[2]], []
      [q[1], q[2]], []

The general broadcasting rules are:

  • If len(qargs) == 1:

    [q[0], q[1]] -> [q[0]],[q[1]]
  • If len(qargs) == 2:

    [[q[0], q[1]], [r[0], r[1]]] -> [q[0], r[0]], [q[1], r[1]]
    [[q[0]], [r[0], r[1]]]       -> [q[0], r[0]], [q[0], r[1]]
    [[q[0], q[1]], [r[0]]]       -> [q[0], r[0]], [q[1], r[0]]
  • If len(qargs) >= 3:

    [q[0], q[1]], [r[0], r[1]],  ...] -> [q[0], r[0], ...], [q[1], r[1], ...]

Parameters

  • qargs (List) – List of quantum bit arguments.
  • cargs (List) – List of classical bit arguments.

Return type

Tuple[List, List]

Returns

A tuple with single arguments.

Raises

CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.

c_if

BooleanExpression.c_if(classical, val)

Set a classical equality condition on this instruction between the register or cbit classical and value val.

Note

This is a setter method, not an additive one. Calling this multiple times will silently override any previously set condition; it does not stack.

control

BooleanExpression.control(num_ctrl_qubits=1, label=None, ctrl_state=None)

Return controlled version of gate. See ControlledGate for usage.

Parameters

  • num_ctrl_qubits (int) – number of controls to add to gate (default=1)
  • label (Optional[str]) – optional gate label
  • ctrl_state (Union[int, str, None]) – The control state in decimal or as a bitstring (e.g. ‘111’). If None, use 2**num_ctrl_qubits-1.

Returns

Controlled version of gate. This default algorithm uses num_ctrl_qubits-1 ancillae qubits so returns a gate of size num_qubits + 2*num_ctrl_qubits - 1.

Return type

qiskit.circuit.ControlledGate

Raises

QiskitError – unrecognized mode or invalid ctrl_state

copy

BooleanExpression.copy(name=None)

Copy of the instruction.

Parameters

name (str) – name to be given to the copied circuit, if None then the name stays the same.

Returns

a copy of the current instruction, with the name

updated if it was provided

Return type

qiskit.circuit.Instruction

from_dimacs_file

classmethod BooleanExpression.from_dimacs_file(filename)

Create a BooleanExpression from the string in the DIMACS format. :type filename: str :param filename: A file in DIMACS format.

Returns

A gate for the input string

Return type

BooleanExpression

Raises

FileNotFoundError – If filename is not found.

inverse

BooleanExpression.inverse()

Invert this instruction.

If the instruction is composite (i.e. has a definition), then its definition will be recursively inverted.

Special instructions inheriting from Instruction can implement their own inverse (e.g. T and Tdg, Barrier, etc.)

Returns

a fresh instruction for the inverse

Return type

qiskit.circuit.Instruction

Raises

CircuitError – if the instruction is not composite and an inverse has not been implemented for it.

is_parameterized

BooleanExpression.is_parameterized()

Return True .IFF. instruction is parameterized else False

mirror

BooleanExpression.mirror()

DEPRECATED: use instruction.reverse_ops().

Returns

a new instruction with sub-instructions

reversed.

Return type

qiskit.circuit.Instruction

power

BooleanExpression.power(exponent)

Creates a unitary gate as gate^exponent.

Parameters

exponent (float) – Gate^exponent

Returns

To which to_matrix is self.to_matrix^exponent.

Return type

qiskit.extensions.UnitaryGate

Raises

CircuitError – If Gate is not unitary

qasm

BooleanExpression.qasm()

Return a default OpenQASM string for the instruction.

Derived instructions may override this to print in a different format (e.g. measure q[0] -> c[0];).

repeat

BooleanExpression.repeat(n)

Creates an instruction with gate repeated n amount of times.

Parameters

n (int) – Number of times to repeat the instruction

Returns

Containing the definition.

Return type

qiskit.circuit.Instruction

Raises

CircuitError – If n < 1.

reverse_ops

BooleanExpression.reverse_ops()

For a composite instruction, reverse the order of sub-instructions.

This is done by recursively reversing all sub-instructions. It does not invert any gate.

Returns

a new instruction with

sub-instructions reversed.

Return type

qiskit.circuit.Instruction

simulate

BooleanExpression.simulate(bitstring)

Evaluate the expression on a bitstring.

This evaluation is done classically.

Parameters

bitstring (str) – The bitstring for which to evaluate.

Returns

result of the evaluation.

Return type

bool

soft_compare

BooleanExpression.soft_compare(other)

Soft comparison between gates. Their names, number of qubits, and classical bit numbers must match. The number of parameters must match. Each parameter is compared. If one is a ParameterExpression then it is not taken into account.

Parameters

other (instruction) – other instruction.

Returns

are self and other equal up to parameter expressions.

Return type

bool

synth

BooleanExpression.synth(registerless=True, synthesizer=None)

Synthesis the logic network into a QuantumCircuit.

Parameters

  • registerless (bool) – Default True. If False uses the parameter names to create registers with those names. Otherwise, creates a circuit with a flat quantum register.
  • synthesizer (Optional[Callable[[BooleanExpression], QuantumCircuit]]) – A callable that takes self and returns a Tweedledum circuit.

Returns

A circuit implementing the logic network.

Return type

QuantumCircuit

to_matrix

BooleanExpression.to_matrix()

Return a Numpy.array for the gate unitary matrix.

Returns

if the Gate subclass has a matrix definition.

Return type

np.ndarray

Raises

CircuitError – If a Gate subclass does not implement this method an exception will be raised when this base class method is called.

validate_parameter

BooleanExpression.validate_parameter(parameter)

Gate parameters should be int, float, or ParameterExpression


Attributes

condition_bits

Get Clbits in condition.

Return type

List[Clbit]

decompositions

Get the decompositions of the instruction from the SessionEquivalenceLibrary.

definition

Return definition in terms of other basic gates.

duration

Get the duration.

label

Return instruction label

Return type

str

params

return instruction params.

unit

Get the time unit of duration.

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