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EquivalenceLibrary

class EquivalenceLibrary(*, base=None)

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A library providing a one-way mapping of Gates to their equivalent implementations as QuantumCircuits.

Create a new equivalence library.

Parameters

base (Optional[EquivalenceLibrary]) – Base equivalence library to will be referenced if an entry is not found in this library.


Methods

add_equivalence

EquivalenceLibrary.add_equivalence(gate, equivalent_circuit)

Add a new equivalence to the library. Future queries for the Gate will include the given circuit, in addition to all existing equivalences (including those from base).

Parameterized Gates (those including qiskit.circuit.Parameters in their Gate.params) can be marked equivalent to parameterized circuits, provided the parameters match.

Parameters

  • gate (Gate) – A Gate instance.
  • equivalent_circuit (QuantumCircuit) – A circuit equivalently implementing the given Gate.

get_entry

EquivalenceLibrary.get_entry(gate)

Gets the set of QuantumCircuits circuits from the library which equivalently implement the given Gate.

Parameterized circuits will have their parameters replaced with the corresponding entries from Gate.params.

Parameters

gate (Gate) – A Gate instance.

Returns

A list of equivalent QuantumCircuits. If empty,

library contains no known decompositions of Gate.

Returned circuits will be ordered according to their insertion in the library, from earliest to latest, from top to base. The ordering of the StandardEquivalenceLibrary will not generally be consistent across Qiskit versions.

Return type

List[QuantumCircuit]

has_entry

EquivalenceLibrary.has_entry(gate)

Check if a library contains any decompositions for gate.

Parameters

gate (Gate) – A Gate instance.

Returns

True if gate has a known decomposition in the library.

False otherwise.

Return type

Bool

set_entry

EquivalenceLibrary.set_entry(gate, entry)

Set the equivalence record for a Gate. Future queries for the Gate will return only the circuits provided.

Parameterized Gates (those including qiskit.circuit.Parameters in their Gate.params) can be marked equivalent to parameterized circuits, provided the parameters match.

Parameters

  • gate (Gate) – A Gate instance.
  • entry (List['QuantumCircuit']) – A list of QuantumCircuits, each equivalently implementing the given Gate.
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