For a link L, the weak splitting number is the minimum number of crossing changes required to change the link into a completely split link, that is, into a collection of knots separated by embedded two-spheres. Unlike the splitting number, crossing changes can occur within a single component as well as between distinct components. The minimum is taken over all diagrams of the link.
The weak splitting number was first studied in . The paper  completed the determination for links of 9 or fewer crossings, with the exception of L9a29, L9a30.
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