The package provides solutions to a number of common
difficulties in writing displayed equations and getting high-
quality output. For example, it is a well-known inconvenience
that if an equation must be broken into more than one line,
'left...right' constructs cannot span lines. The breqn package
makes them work as one would expect whether or not there is an
intervening line break. The single most ambitious goal of the
package, however, is to support automatic linebreaking of
displayed equations. Such linebreaking cannot be done without
substantial changes under the hood in the way formulae are
processed; the code must be watched carefully, keeping an eye
on possible glitches. The bundle also contains the flexisym and
mathstyle packages, which are both designated as support for
breqn.
