diff --git a/qiskit/circuit/__init__.py b/qiskit/circuit/__init__.py index ebaef39c2a43..22a771a67312 100644 --- a/qiskit/circuit/__init__.py +++ b/qiskit/circuit/__init__.py @@ -454,7 +454,7 @@ :class:`Instruction`\ s can be related to other circuits to provide a decompositions by using their :attr:`Instruction.definition` attribute, which provides a local, one-off decomposition. This can be in whatever basis set of operations is most convenient to you, as long as the definitions of -all contained gates have some topological order; that is, you cannot use a gate in a definition it +all contained gates have some topological order; that is, you cannot use a gate in a definition if its own definition depends on the parent. If the :class:`Instruction` should be considered entirely opaque to optimizers, its :attr:`~Instruction.definition` can be ``None``. See :ref:`circuit-custom-gates` for more detail.