\fussy & \sloppy ¶Declarations to make TeX more picky or less picky about line
breaking. Declaring \fussy usually avoids too much space between
words, at the cost of an occasional overfull box. Conversely,
\sloppy avoids overfull boxes while suffering loose interword
spacing.
The default is \fussy. Line breaking in a paragraph is
controlled by whichever declaration is current at the end of the
paragraph, i.e., at the blank line or \par or displayed
equation ending that paragraph. So to affect the line breaks, include
that paragraph-ending material in the scope of the command.