Math/basic

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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 x2
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]