`~`

, `\nobreakspace`

¶Synopsis:

before~after

The *tie* character, `~`

, produces a space between `before` and
`after` at which the line will not be broken. By default the white
space has length 3.33333pt plus 1.66666pt minus
1.11111pt (see Lengths). The command `\nobreakspace`

and the Unicode input character U+00A0 (also in many 8-bit encodings)
are synonyms.

Note that the word ‘`tie`’ has this meaning in the TeX/Texinfo
community; this differs from the typographic term “tie”, which
is a diacritic in the shape of an arc, called a “tie-after” accent
in The TeXbook.

Here LaTeX will not break the line between the final two words:

Thanks to Prof.~Lerman.

In addition, despite the period, LaTeX does not use the
end-of-sentence spacing (see `\@`

).

Ties prevent a line break where that could cause confusion. They also
still allow hyphenation (of either of the tied words), so they are
generally preferable to putting consecutive words in an `\mbox`

(see `\mbox`

& `\makebox`

).

Exactly where ties should be used is something of a matter of taste, sometimes alarmingly dogmatic taste, among readers. Nevertheless, here are some usage models, many of them from The TeXbook.

- Between an enumerator label and number, such as in references:
`Chapter~12`

, or`Theorem~\ref{th:Wilsons}`

, or`Figure~\ref{fig:KGraph}`

. - When cases are enumerated inline:
`(b)~Show that $f(x)$ is (1)~continuous, and (2)~bounded`

. - Between a number and its unit:
`$745.7.8$~watts`

(the`siunitx`

package has a special facility for this) or`144~eggs`

. This includes between a month and day number in a date:`October~12`

or`12~Oct`

. In general, in any expressions where numbers and abbreviations or symbols are separated by a space:`AD~565`

, or`2:50~pm`

, or`Boeing~747`

, or`268~Plains Road`

, or`\$$1.4$~billion`

. Other common choices here are a thin space (see`\thinspace`

&`\negthinspace`

) and no space at all. - When mathematical phrases are rendered in words:
`equals~$n$`

, or`less than~$\epsilon$`

, or`given~$X$`

, or`modulo~$p^e$ for all large~$n$`

(but compare`is~$15$`

with`is $15$~times the height`

). Between mathematical symbols in apposition with nouns:`dimension~$d$`

or`function~$f(x)$`

(but compare`with length $l$~or more`

). When a symbol is a tightly bound object of a preposition:`of~$x$`

, or`from $0$ to~$1$`

, or`in common with~$m$`

. - Between symbols in series:
`$1$,~$2$, or~$3$`

or`$1$,~$2$, \ldots,~$n$`

. - Between a person’s given names and between multiple surnames:
`Donald~E. Knuth`

, or`Luis~I. Trabb~Pardo`

, or`Charles~XII`

—but you must give TeX places to break the line so you might do`Charles Louis Xavier~Joseph de~la Vall\'ee~Poussin`

.