Documentation
Publicon
User Guide
Advanced Features
Editing and Formatting Notebooks
Notebooks and Cells
Working with Notebooks and Cells
Cell Grouping
Cells can be arranged in hierarchical groups with several cells of different styles being enclosed inside a cell of another style. The grouping of cells is indicated by nested brackets on the right.
A group of cells can be either open or closed. When a cell group is open, all cells within it can be seen explicitly. To close the group, double-click the outermost bracket. When a cell group is closed, only the first (or header) cell in the group can be seen.
When a group of cells is closed, the bracket enclosing it has an arrow at the bottom. You can double-click the arrow or the outer bracket itself to open the group. Large notebooks are often distributed with many closed groups of cells so that you see only an outline of the contents. You can then open the cell groups you are interested in viewing by double-clicking the appropriate brackets.
To control the grouping of cells, use the Cell 
Grouping submenu. The default setting for cell grouping is Automatic; that is, all cells entered into a document are automatically arranged hierarchically in groups according to their styles.
Automatic grouping of cells takes place according to a set of precedence rules specified in the style sheet for the notebook. Each cell style is given a specific number for the option CellGroupingRules. The lower the value of this number, the higher the precedence of that cell style. When you enter cells into the notebook, all cells of a certain style are grouped together under the most recent cell of a higher precedence.
For example, in the default style sheet, Text cells entered after a Subsection cell are grouped under that Subsection cell. Similarly, several Subsection cells would be grouped under a cell style having higher precedence, such as a Section or Subtitle cell.
You can also group and ungroup cells manually by choosing Cell Grouping Manual. Once in this mode you can
• combine adjacent cells into a single group by choosing Cell Grouping Group Cells.
• ungroup cells by choosing Cell Grouping Ungroup Cells.
If you want to divide a single cell into two cells, select a part of the text inside the target cell and choose Cell Divide.
