On self \(\Delta\)-equivalence of boundary links (Q1568361)

The author considers boundary links in \(\mathbb R^3\), and asks whether they are equivalent in a certain sense (\(\Delta\)-equivalence) to trivial links. This equivalence is generated by a local process introduced in [\textit{H. Murakami} and \textit{Y. Nakanishi}, Math. Ann. 284, No. 1, 75-89 (1989; Zbl 0646.57005)]. He gives a proof for \(2\)-component boundary links ``in the strong sense'' where the surfaces spanning the different components are replaced by singular disks.