对称逆半群的Sierpienski秩
Sierpiński rank of the Symmetric inverse semigroup
摘要：
我们证明了从一个无限集到它自身的部分双射的每一个可数集都可以作为两个这样的部分双射的合成而得到。这加强了Higgins，Howie，Mitchell和Ruškuc的一个结果，即每一个这样的可数的部分双射集都可以作为两个部分双射及其逆的合成而得到。
英文摘要：
We show that every countable set of partial bijections from an infinite set to itself can be obtained as a composition of just two such partial bijections. This strengthens a result by Higgins, Howie, Mitchell and Ruškuc stating that every such countable set of partial bijections may be obtained as the composition of two partial bijections and their inverses.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
