Guide to LaTeX (4th Edition) (Tools and Techniques

516 Appendix H. Command Summary
\begin{envrnmnt} . . . . . . . . . . . . . . . . . . . . (2.2) – 19
Start of an environment with the name envrnmnt. This command
must be coupled with \end{envrnmt} to terminate the environment.
The environment name in both these commands must be identical.
\begin{abstract} . . . . . . . . . . . . . . . . . . . . (3.3.2) – 55
Start of the environment abstract to produce an abstract. With
document class article, font size \small and the quotation environment
are selected. With report, the abstract appears on a
separate page with normal font size and line width. In both cases,
the heading Abstract is centered above the text.
\begin{align} [a] . . . . . . . . . . . . . . . . . . (12.2.6) – 274
With the amsmath package, switches to displayed math mode to produce
a set of aligned equations. Line are terminated by \\ commands.
The lines are split into columns aligned on the first, third, fifth . . . &
characters. Each line receives an equation number unless the *-form
of the environment has been selected.
\begin{alignat}{num} [a] . . . . . . . . . . . . . (12.2.6) – 275
Is the same as the align environment except that no spacing is
inserted automatically between the column pairs. The argument num
is the number of column pairs = (1 + n&)/2 where n& is the number
of & signs in one row. Explicit spacing may be placed between column
pairs, especially if the left part of that pair is otherwise empty.
\begin{aligned}[pos] [m][a] . . . . . . . . . . . . (12.2.6) – 276
With the amsmath package, is like the align environment but is
used as an element within math mode. The optional argument pos
determines the vertical positioning relative to neighboring elements:
t or b for top or bottom, no argument for centering.
\begin{appendix} . . . . . . . . . . . . . . . . . . . . (3.3.4) – 57
Start of the environment appendix to produce an appendix. The
main section counter is reset to zero and its numbering appears as
capital letters.
\begin{array}[pos]{col} [m] . . . . . . . . (4.8.1), (5.4.3) – 95, 134
Start of the environment array to produce matrices and arrays in
math mode. The column definition col contains a formatting character
for each column. Thus \begin{array}{lcr} produces an array
with three columns: one left justified, one centered, and one right
justified. The optional parameter pos determines how the array is
aligned vertically with text outside it on the same line: t with the top
line, b with the bottom line, while the default is with the center. See
also \begin{tabular}
\begin{center} . . . . . . . . . . . . . . . . . . . . . (4.2.1) – 67
Start of the environment center. Each line of text terminated by \\
appears centered. See also \centering.