To quote from the Comprehensive Symbols List (which has these symbols listed as ”frequently requested”):
The characters “<”, “>”, and “|” do
work as expected in math mode,
although they produce, respectively,
“¡”, “¿”, and “—” in text mode when
using the OT1 font encoding.
The following are some alternatives for
typesetting “<”, “>”, and “|”:
- Specify a document font encoding other
than OT1 (as described on page 8).
- Use the appropriate symbol commands
from Table 2 on page 9, viz.
\textless
, \textgreater
, and \textbar
.
- Enter the symbols in math mode
instead of text mode, i.e.,
$<$
, $>$
,
and $|$
.
Note that for typesetting
metavariables many people prefer
\textlangle
and \textrangle
to
\textless
and \textgreater
; i.e., “〈filename〉” instead of “<filename>”.
From page 8 (with strong recommendations that you should use this):
One note that appears a few times in
this document, particularly in Section
2, indicates that certain symbols do
not exist in the OT1 font encoding
(Donald Knuth’s original, 7-bit font
encoding, which is the default font
encoding for LaTeX) and that you
should use fontenc
to select a
different encoding, such as T1 (a
common 8-bit font encoding). That
means that you should put
“\usepackage[ encoding ]{fontenc}
” in
your document’s preamble, where
encoding
is, e.g., T1
or LY1
. To limit
the change in font encoding to the
current group, use “\fontencoding{ encoding }\selectfont
”.
As Will notes in the comments, a good solution to this is to put
\usepackage[T1]{fontenc}
\usepackage{lmodern}
into your preamble.
Alternatively, using XeLaTeX or LuaLaTeX with the fontspec
package also makes these symbols (and many more) work correctly.
Note that the document uses Springer's LNCS style. In this style, all Greek letters are in italics, and vectors are denoted by boldface.
Most likely the bold italic Delta is produced in this particular case by something similar to this:
\documentclass{llncs}
\begin{document}
$\vec{\Delta}$
\end{document}
The result is:
Note that if you used the article
class, the same code would produce a normal Delta with an arrow:
Best Answer
One option:
Of course, define a command:
Or (should "FP" and "TP" be fixed):
I'm not sure of the font that should be used for "FP" and "TP", but that is up to their meaning; is they should be treated like text, then
\text{FP}
and\text{TP}
should be used.