Ties avoid bad line breaks
- Use ties in cross-reference: Theorem~A; Algorithm~B;
Chapter~3; Table~4; Programs E and~F. No tie appears after
"Programs" in the last example since it is acceptable to
have "E and F" at the beginning of a
- Use ties between a person's forenames and between
multiple surnames: Dr.~I.~J. Matrix; Luis~I. Trabb~Pardo;
Peter van~Emde~Boas. It is better to hyphenate a
name rather than to break it between words.
- Use ties for symbols in apposition with nouns:
base~b; dimension~d; function~f(x);
string~s of length~l. But compare the last
example with "string~s of length l~or
- Use ties for symbols in series: 1,~2, or~3; a,~b, and~c;
- Use ties for symbols as tightly-bound objects of
prepositions: of~x; from 0 to~1; increase z
by~1; in common with~m. This rule does not apply to
compound objects: for example, consider "of u~and~v".
- Use ties to avoid breaking up mathematical phrases that
involve words: equals~n; less than~e;
mod~2; modulo~pe; (given~X); when x~grows;
if t~is... Further, "for all large~n" and "for all
n~greater than~n0". But what you
tie depends upon the context: sometimes "is~15" is correct,
but here prefer "is 15~times the height".
- Use ties when enumerating cases: "(b)~Show that
f(x) is (1)~continuous; (2)~bounded.
I took this list of examples from pp. 89--90 of Digital typography by D. E. Knuth, CSLI Publications, 1999; originally written with M. F. Plass and appearing in Software---Practice and Experience 11 (1981), 1119--1184. Also see Chapter 14 in The TeXbook by D. E. Knuth, Amer. Maths Soc. (1986).