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

12.2. Standard features of A M S-L AT E X 267
\hdotsfor[2.0]{4}\\
a_{q_kq_1} & a_{q_kq_2} & \dots & a_{q_kq_k}
\end{vmatrix} \]
Comparing this input text with that on page 134, one sees that it
is simpler and easier to follow. The only new command used here is
\hdotsfor which has the syntax
\hdotsfor[stretch]{n}
and which prints a continuous line of dots through n columns. The
optional argument stretch is a multiplicative number to increase the dot
density, being 1.0 by default.
\[ \begin{matrix} a & b & c & d & e\\
x & \hdotsfor{3} & z
\end{matrix} \]
a b c d e
x . . . . . . . . . z
Compare the standard dot spacing above with that from \hdotsfor[2.0]
in the previous example.
The initial letter of each of the xmatrix environments indicates the
type of braces that enclose it: pmatrix for (round) parentheses, bmatrix
for (square) brackets, Bmatrix for (curly) braces, vmatrix for vertical
lines, and Vmatrix for double vertical lines. They appear as
r s t
u v w
x y z
⎧
⎪⎨ r s
⎫
t ⎪⎬
u
⎪⎩
x
v
y
w
⎪⎭
z
⎛
r
⎜
⎝u
s
v
⎞
t
⎟
w⎠
x y z
r
u
x
s
v
y
t
w
z
where each matrix has been produced with
⎡
r
⎢
⎣u
s
v
⎤
t
⎥
w⎦
x y z
r
u
x
s
v
y
t
w
z
\[ \begin{xmatrix} r & s & t\\ u & v & w\\ x & y & z
\end{xmatrix} \]
where xmatrix is set to matrix, pmatrix, bmatrix, Bmatrix, vmatrix,
and Vmatrix one after the other.
To generate a small array within a text formula, one can apply the
smallmatrix environment. In this way
a b c
e m r can be made with
$ \bigl( \begin{smallmatrix} a & b & c\\ e & m & r
\end{smallmatrix} \bigr) $
12.2.5 User extensions and fine adjustments
Function names
Standard LAT Package:
EX recognizes a number of preprogrammed function names
amsopn (Section 5.3.8) that are printed in math made by placing a backslash in