EQN(1) User Commands EQN(1)

## NAME

eqn, neqn, checkeq - typeset mathematics test

## SYNOPSIS

**eqn **[**-d **__xy__] [ **-f **__n__] [**-p **__n__] [ **-s **__n__] [__file__]...

**neqn **[__file__]...

**checkeq **[__file__]...

## DESCRIPTION

**eqn **and **neqn **are language processors to assist in describing equations.

**eqn **is a preprocessor for troff(1) and is intended for devices that can

print**troff**'s output. **neqn **is a preprocessor for nroff(1) and is

intended for use with terminals. Usage is almost always:

example%**eqn file ... | troff**

example%**neqn file ... | nroff**

If no__file__s are specified, **eqn **and **neqn **read from the standard input. A

line beginning with**.EQ **marks the start of an equation. The end of an

equation is marked by a line beginning with**.EN**. Neither of these lines

is altered, so they may be defined in macro packages to get centering,

numbering, and so on. It is also possible to set two characters as

``delimiters''; subsequent text between delimiters is also treated as**eqn**

input.

**checkeq **reports missing or unbalanced delimiters and **.EQ**/**.EN **pairs.

## OPTIONS

The following options are supported:

**-d**__xy__

Sets equation delimiters set to characters__x__ and __y__ with the

command-line argument. The more common way to do this is with

**delim **__xy__ between **.EQ **and **.EN**. The left and right delimiters may

be identical. Delimiters are turned off by**delim off **appearing

in the text. All text that is neither between delimiters nor

between**.EQ **and **.EN **is passed through untouched.

**-f**__n__

Changes font to__n__ globally in the document. The font can also be

changed globally in the body of the document by using the**gfont**

__n__ directive, where __n__ is the font specification.

**-p**__n__

Reduces subscripts and superscripts by__n__ point sizes from the

previous size. In the absence of the**-p **option, subscripts and

superscripts are reduced by 3 point sizes from the previous

size.

**-s**__n__

Changes point size to__n__ globally in the document. The point size

can also be changed globally in the body of the document by

using the**gsize **__n__ directive, where __n__ is the point size.

## OPERANDS

The following operands are supported:

__file__

The nroff or troff file processed by**eqn **or **neqn**.

## EQN LANGUAGE

The nroff version of this description depicts the output of**neqn **to the

terminal screen exactly as**neqn **is able to display it. To see an

accurate depiction of the output, view the printed version of this page.

Tokens within**eqn **are separated by braces, double quotes, tildes,

circumflexes, SPACE, TAB, or NEWLINE characters. Braces {} are used for

grouping. Generally speaking, anywhere a single character like__x__ could

appear, a complicated construction enclosed in braces may be used

instead. A tilde (**~**) represents a full SPACE in the output; a circumflex

(**^**) half as much.

**Subscripts and superscripts:**

These are produced with the keywords**sub **and **sup**.

**x sub i**

makes__x_____i__

**a sub i sup 2**

produces__a_____i__^2

**e sup {x sup 2 + y sup 2}**

gives e^(x^2+y^2)

**Fractions:**

Fractions are made with**over**.

**a over b**

yields__a__/__b__

**Square Roots:**

These are made with**sqrt**

**1 over sqrt {ax sup 2 +bx+c}**

results in 1/sqrt(__ax__^2 + __bx__ + __c__)

**Limits:**

The keywords**from **and **to **introduce lower and upper limits on

arbitrary things:

**lim from {n-> inf } sum from 0 to n x sub i**

makes lim_(__n__ -> oo) E_0^__n__ __x_____i__

**Brackets and Braces:**

Left and right brackets, braces, and the like, of the right height

are made with**left **and **right**.

**left [ x sup 2 + y sup 2 over alpha right ] ~=~1**

produces [__x__^2 + (__y__^2)/a] = 1

The**right **clause is optional. Legal characters after **left **and

**right **are braces, brackets, bars, **c **and **f **for ceiling and floor,

and**"" **for nothing at all (useful for a right-side-only bracket).

**Vertical piles:**

Vertical piles of things are made with**pile**, **lpile**, **cpile**, and

**rpile**.

**pile {a above b above c}**

produces__a__ __b__ __c__

There can be an arbitrary number of

elements in a pile.**lpile **left-

justifies,**pile **and **cpile **center, with

different vertical spacing, and**rpile**

right justifies.

**Matrices:**

Matrices are made with**matrix**.

**matrix { lcol { x sub i above y sub 2 } ccol { 1 above 2 } }**

produces (__x_____i__ __y___2) (1 2)

In addition, there is**rcol **for a right-justified column.

**Diacritical marks:**

Diacritical marks are made with**dot**, **dotdot**, **hat**, **tilde**, **bar**, **vec**,

**dyad**, and **under**.

**x dot = f(t) bar**

is__x__. = __f__ ( __t__ )-

**y dotdot bar ~=~ n under**

is__y__"- = __n___

**x vec ~=~ y dyad**

is__x__-> = __y__<->

**Sizes and Fonts:**

Sizes and font can be changed with**size **__n__ or **size +-**__n,__ **roman**, **italic**,

**bold**, and **font **__n__. Size and fonts can be changed globally in a

document by**gsize **__n__ and **gfont **__n__, or by the command-line arguments **-s**__n__

and**-f**__n.__

**Successive display arguments:**

Successive display arguments can be lined up. Place**mark **before the

desired lineup point in the first equation; place**lineup **at the place

that is to line up vertically in subsequent equations.

**Shorthands:**

Shorthands may be defined or existing keywords redefined with**define**__:__

**define **__thing__ **% **__replacement__ **%**

Defines a new token called__thing__ which will be replaced by

__replacement__ whenever it appears thereafter. The **% **may be any

character that does not occur in__replacement__.

**Keywords and Shorthands:**

Keywords like**sum int inf **and shorthands like **>= -> **and **!= **are

recognized.

**Greek letters:**

Greek letters are spelled out in the desired case, as in**alpha **or

**GAMMA**.

**Mathematical words:**

Mathematical words like**sin**, **cos**, and **log **are made Roman

automatically.

troff(1) four-character escapes like +o (+o) can be used anywhere. Strings

enclosed in double quotes**"**...**" **are passed through untouched; this

permits keywords to be entered as text, and can be used to communicate

with**troff **when all else fails.

## SEE ALSO

nroff(1), tbl(1), troff(1), attributes(5), ms(5)

## BUGS

To embolden characters such as digits and parentheses, it is necessary

to quote them, as in `**bold "12.3"**'.

July 12, 2002 EQN(1)

eqn, neqn, checkeq - typeset mathematics test

intended for use with terminals. Usage is almost always:

example%

example%

If no

line beginning with

equation is marked by a line beginning with

is altered, so they may be defined in macro packages to get centering,

numbering, and so on. It is also possible to set two characters as

``delimiters''; subsequent text between delimiters is also treated as

input.

The following options are supported:

Sets equation delimiters set to characters

command-line argument. The more common way to do this is with

be identical. Delimiters are turned off by

in the text. All text that is neither between delimiters nor

between

Changes font to

changed globally in the body of the document by using the

Reduces subscripts and superscripts by

previous size. In the absence of the

superscripts are reduced by 3 point sizes from the previous

size.

Changes point size to

can also be changed globally in the body of the document by

using the

The following operands are supported:

The nroff or troff file processed by

The nroff version of this description depicts the output of

terminal screen exactly as

accurate depiction of the output, view the printed version of this page.

Tokens within

circumflexes, SPACE, TAB, or NEWLINE characters. Braces {} are used for

grouping. Generally speaking, anywhere a single character like

appear, a complicated construction enclosed in braces may be used

instead. A tilde (

(

These are produced with the keywords

makes

produces

gives e^(x^2+y^2)

Fractions are made with

yields

These are made with

results in 1/sqrt(

The keywords

arbitrary things:

makes lim_(

Left and right brackets, braces, and the like, of the right height

are made with

produces [

The

and

Vertical piles of things are made with

produces

There can be an arbitrary number of

elements in a pile.

justifies,

different vertical spacing, and

right justifies.

Matrices are made with

produces (

In addition, there is

Diacritical marks are made with

is

is

is

Sizes and font can be changed with

document by

and

Successive display arguments can be lined up. Place

desired lineup point in the first equation; place

that is to line up vertically in subsequent equations.

Shorthands may be defined or existing keywords redefined with

Defines a new token called

character that does not occur in

Keywords like

recognized.

Greek letters are spelled out in the desired case, as in

Mathematical words like

automatically.

troff(1) four-character escapes like +o (+o) can be used anywhere. Strings

enclosed in double quotes

permits keywords to be entered as text, and can be used to communicate

with

nroff(1), tbl(1), troff(1), attributes(5), ms(5)

To embolden characters such as digits and parentheses, it is necessary

to quote them, as in `

July 12, 2002 EQN(1)