Math/basic
Contents
Binary Operators Relations
Basic binary symbols can be produced by typing the correspoding keyboard character. These include
+ - = < >
A general expressions can be input in the natural manner. For example $x+y$
gives . Notice that TeX took care of the spacing around +
. Mathematicians use a lot of symbols that are not avialable on the keyboard. TeX (and ConTeXt) provide macros to input them. For example $x \times y$
gives . The following is a parial list of frequently used binary operators and relations.
Commonly Used Binary Operators | Commonly used relation symbols | Set Relations | |||
---|---|---|---|---|---|
\pm | \leq | \subset | |||
\mp | \ll | \subseteq | |||
\times | \geq | \supset | |||
\div | \gg | \supseteq | |||
\ast | \equiv | \cap | |||
\star | \sim | \cup | |||
\bullet | \simeq | \in |
|||
\circ | \approx | ||||
\cdot | \neq |
Sums, products, integrals
Sums with \sum
\setupbodyfont[14pt] \framed[frame=off,align=normal]{% \m{\sum_{k = 0}^{j + n} a_k = e^{a + b - c}} \blank[small] \dm{\sum_{k = 0}^{j + n} a_k = e^{a + b - c}}}
Products with \prod
\setupbodyfont[14pt] \framed[frame=off,align=normal]{% \m{\prod_{i=a}^{b} f(i)} \blank[small] \dm{\prod_{i=a}^{b} f(i)}}
Integrals with \int
\setupbodyfont[14pt] \framed[frame=off,align=normal]{% \m{\int_a^b f(x) \dd x } \blank[small] \dm{\int_a^b f(x) \dd x } \blank[small] \setupmathematics[differentiald=upright] \dm{\int_a^b f(x) \dd x } \blank[small] }
Greek Letters
To type the greek character α you can say $\alpha$
which gives . If you have a utf enabled keyboard, you can also type the α directly and ConTeXt will correctly interpret it. For example,
\enableregime[utf] Here is some Greek math $α^2 + β^2 = γ^2$
Here is a complete list of greek letters
lowercase greek letters | variation | uppercase greek letters | |||
---|---|---|---|---|---|
\alpha | |||||
\beta | |||||
\gamma | \Gamma | ||||
\delta | \Delta | ||||
\epsilon | \varepsilon | ||||
\zeta | |||||
\eta | |||||
\theta | \vartheta | \Theta | |||
\iota | |||||
\kappa | |||||
\lambda | \Lambda | ||||
\mu | |||||
\nu | |||||
\xi | \Xi | ||||
\omicron | |||||
\pi | \varpi | \Pi | |||
\rho | \varrho | ||||
\sigma | \varsigma | \Sigma | |||
\tau | |||||
\upsilon | \Upsilon | ||||
\phi | \Phi | ||||
\chi | |||||
\psi | \Psi | ||||
\omega | \Omega |
Subscript and superscript
TeX uses ^
and _
to denote superscipts and subscipts. It is perhaps easiest to explain this by means of some examples. is written as $x_{10}^{15}$
or $x^{15}_{10}$
. The order in which _
and ^
are given does not matter. One can also type complicated expressions like as $a_{b_{c_{d_{e}}}}$
.
To align superscripts and subscripts one after the other (not above/below each other), add empty braces {}
after each of them as $T^a{}_b{}^c{}$
to obtain . This effectively adds each index as superscript/subscript of the empty braces rather than the main character, thus aligning them separately and avoiding double superscript errors.
List of All Math macros
With \usemodule[fnt-25]
, \showmathfontcharacters produces a lengthy annotated catalogue.
Here is the first page:
In ConTeXt MkII, you can see the list of all math macros by \showmathcharacters.
Spacing
TeX handles math spacing by breaking a formula into parts, and assigning each of those parts a role such as 'Ord' (a variable or number) or 'Rel' (equality, larger than, et cetera). For each combination of roles, it then looks up the spacing appropriate between them in a table. These are the roles:
Ord | e.g. 4 or a or x^{2} |
Op | Unary operators such as sin or ln. |
Bin | Binary operators such as '+' |
Rel | Relationships such as '=' or '>' or '\implies' |
Open | open brackets of any kind |
Close | closing brackets of any kind |
Punct | Punctuation: digit separators like '.' or ','. |
Inner | Fractions are inner. What else is inner? |
To set up e.g. the spacing between ordinal items, do as follows (since dec 2012):
\startsetups math:morespacing \ordordspacing\textstyle 1mu plus .5mu minus .25mu\relax \stopsetups
\setupmathematics [setups=math:morespacing]