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arXiv 1802.10331cs.LOcs.DM
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在弦无爪图上捕获对数空间与多项式时间

Capturing Logarithmic Space and Polynomial Time on Chordal Claw-Free Graphs

Berit Grußien

AI总结:

本文证明弦无爪图类允许LREC$_=$可定义的规范化,从而存在对数空间规范化算法和同构测试,并由此捕获对数空间;由于LREC$_=$包含于带计数的定点逻辑,后者在该图类上捕获多项式时间。

摘要:

我们证明了弦无爪图类允许LREC$_=$可定义的规范化。LREC$_=$是一种通过一个运算符扩展带计数的一阶逻辑的逻辑,该运算符允许其形式化一种有限形式的递归。这个运算符可以在对数空间中求值。由此可知,对于弦无爪图类,存在一个对数空间规范化算法,因此也存在一个对数空间同构测试。作为进一步的结果,LREC$_=$在该图类上捕获对数空间。由于LREC$_=$包含在带计数的定点逻辑中,我们还得到带计数的定点逻辑在弦无爪图类上捕获多项式时间。

英文摘要:

We show that the class of chordal claw-free graphs admits LREC$_=$-definable canonization. LREC$_=$ is a logic that extends first-order logic with counting by an operator that allows it to formalize a limited form of recursion. This operator can be evaluated in logarithmic space. It follows that there exists a logarithmic-space canonization algorithm, and therefore a logarithmic-space isomorphism test, for the class of chordal claw-free graphs. As a further consequence, LREC$_=$ captures logarithmic space on this graph class. Since LREC$_=$ is contained in fixed-point logic with counting, we also obtain that fixed-point logic with counting captures polynomial time on the class of chordal claw-free graphs.

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。

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