# What algorithm does Qiskit use to decompose arbitrary n-qubit unitaries on Rotations + CNOT?

I found that Qiskit uses Unroll3qOrMore in the transpiler class function to decompose an arbitrary $$n > 2$$ unitary and represent it as a directed acyclic graph (DAG). But I can't find an algorithm (or paper for it). Could you help?

For $$n > 2$$ qubit gates the Qiskit transpiler uses column-by-column decomposition (see: https://arxiv.org/pdf/1501.06911.pdf).