Separating a chart

Abstract

In this paper, we shall show a condition for that a chart is C-move equivalent to the product of two charts, the union of two charts ${\Gamma }^{\ast }$ and ${\Gamma }^{\ast \ast }$ which are contained in disks $D^{\ast }$ and $D^{\ast \ast }$ with $D^{\ast }\cap D^{\ast \ast }=\varnothing$.

22 pages, 7 figures