Information Technology Reference
In-Depth Information
Readability
Mathematics is usually presented in italics, to distinguish it from other text. For
example, in the expression “of length
n
” it is clear that
n
is a variable of some kind.
The main exception is function names such as log or sin, which are written in an
upright font. Always use the same font for the same variable, and use the same font
for all variables unless there is a good reason not to. There are several standards
for representing a vector variable, such as
u
u
. (The tilde was originally an
instruction to the typesetter to choose a bold font.) Follow the conventions of your
area rather than invent your own.
Brackets or square brackets
,
u
ǜ
, and
are used to delimit
subexpressions, but braces can be confusing because they are also used to denote
sets. To ensure that sets are distinguished from sequences, use braces for sets and
parentheses for sequences. Angle brackets
[]
, parentheses
()
, and braces
{}
can also be used; these are not the
same symbols as the relational operators
<>
. Note that some authors choose
for
=
i
u
i
v
i
.
Use parentheses of appropriate size; they should stand out from the expressions
they enclose.
the inner product of vectors:
u
,
v
·
(
i
=
0
A
i
))
(
p
·
(
i
=
0
A
i
)
Sentences with embedded mathematics should be structured as if each formula is
a simple phrase. Phrases indicate how the following text will be structured, but
mathematics does not, and so should not be used at the start of a sentence.
p
q
n
is a conditional dependency.
The dependency
p
p
ₐ
q
1
∧···∧
q
n
is conditional.
The same rule applies to digits; sentences should begin with a word.
ₐ
q
1
∧···∧
7 of the runs were successful, but 46 failed.
Seven of the runs were successful, but 46 failed.
There were 7 successful runs and 46 failures.
The first attempt at rephrasing fixes one problem but creates another, by introducing a
mismatch in the way the numbers are described. In this case, a full rewrite is required.
Give the type of each variable every time it is used, so that the reader doesn't
have to remember as many details and can concentrate on understanding the content.
Watch out for misplaced types or variables.
The values are represented as a list of numbers
L
.
The values are represented as a list
L
of numbers.
The values are represented as
L
, a list of numbers.
The former version is ambiguous—the symbol
L
might denote an individual member
of the set.
