*not*case sensitive. In a pattern

`|`

means *OR*(slower),

` \b `

matches a word "boundary". Accented characters (umlauts, etc.) are not found -- but see
Patterns with Accents below for some tricks.pattern finds ------- ------------------------------------------ ring ring rings bring string scattering Springer etc. \bring ring rings (but not: bring scattering Springer or string) ring\b ring bring string scattering (but not: rings or Springer) \bring\b ring Ring RING (but not: rings bring etc.) algebraic sy algebraic systems algebraic symbols etc. modu|gauss unimodular Gauss gaussian etc. [NO extra spaces around | ]The more complicated pattern:

representation|lie groups|lie algebra|cohomology|deformationtoday located all books (about 350) with any of representation, Lie groups, Lie algebra, cohomology, or deformation in their title or as their subject.

Notes: Some MR class descriptions (and other data) are in the data base but are not printed out. However you can use these in a search
pattern (Example 5 and last Example above). A search may "mysteriously" match because of the data we do not print.

If you also enter a *second pattern*, the (faster) search will match only if BOTH patterns are found. For instance if the first
pattern is ` riemann`

and the second pattern is ` geometry `

, then it will only match entries in which both ```
riemann
```

AND ` geometry `

occur somewhere (case insensitive always). This runs faster if the *least* likely
pattern is placed first. Thus, `riemann`

AND `geometry`

runs faster than `geometry`

AND `riemann`

.

## Patterns with Accents

In most cases, to search for a name that has an accented character, such as Poincaré or Kähler, you can substitute an
unaccented character, so Poincare or Kahler should work. Another procedure is to use only a portion of the name that does not contain
any accented character; thus `poincar`

and `hler`

might be used for Poincaré or Kähler.

A better procedure is to substitute a "wild card" for the accented character: replace each accented character by `\S*`

. Thus
search for `poincar\S*`

and `k\S*hler`

This procedure will even catch versions such as *Kaehler* where an
additional letter has been used.

## Patterns with En-dashes

Type two dashes for an en-dash, e.g., Cohen`--`

Macaulay.

EXPERTS: these are perl patterns. You can look in the Unix man page for perl for more hints on patterns (see "Regular Expression" in the perl man page Perl Manual).