Typing a diagram.

Let us assume you have determined the nature and the position of each item of your diagram. Here is what you should type in order to give that information to the Diagram Macros.

1. Type the command ++ to start the typing of the diagram; this command will in particular start a center environment; it can be given both in paragraph and in math mode.
2. Type between curly brackets the description of every item; this description will automatically be processed in Math mode. The empty items will thus appear as {} in your input.
3. Separate two consecutive items in a same row by the ``next item command'', which is ++. The command ++ may not appear before the first item of a row nor after the last item of a row.
4. Separate two consecutive rows of items by the ``next row command'' which is ++. The command ++ may not appear before the first row of items nor after the last row of items.
5. Type the command ++ to indicate the end of the diagram typing.

When you type a diagram using the procedure just indicated, notice that between the two commands ++ and ++

• You can put as much space as you want in a line to make your input file easier to read;
• You should never use a $ sign to type a mathematical symbol, except if you did include that symbol in a box.

With all that in mind, the diagram of the previous section can be typed as follows

\DIAG
{X}                                                     \nn
{} \n{\Sedotar{z}}\n{\Esear{y}}                         \nn
{} \n{\sseaR{x}}  \n{P}        \n{\Eepi{k}}\n{B}        \nn
{} \n{}           \n{\Smono{h}}\n{}        \n{\smonO{g}}\nn
{} \n{}           \n{A}        \n{\eepI{f}}\n {C}
\diag

\DIAG{X}\n{}\n{}\n{}\n{}\nn{}\n{\Sedotar{z}}
\n{\Esear{y}}\n{}\n{}\nn{}\n{\sseaR{x}}\n{P}
\n{\Eepi{k}}\n{B}\nn{}\n{}\n{\Smono{h}}\n{}
\n{\smonO{g}}\nn{}\n{}\n{A}\n{\eepI{f}}\n{C}\diag

The Diagram Macros will automatically center the diagram horizontally on the page and will take care of the spacing with the preceeding and the following text. When a diagram is rather big, you should make it a figure or a table (see L^ATEXbook, 3.5.1 page 60) to improve the quality of the page-making. If you want to align horizontally various small diagrams, consider these just as a unique wide diagram where some columns are completely empty.