I just noticed that several webwork problems do not display the left/right braces (for sets) in several problems. Here are snippets of the relevant codes (the double quotes are part of the original codes):
"\( $lbrace x \in \mathbb{R} \mid x^2-2=0 $rbrace\)"
"\( $LBRACE x \in \mathbb{Q} \mid x^2-2=0 $RBRACE\)"
"\($LB 3 $RB \) is an element of \($LB $LB 3 $RB $RB\)."
In case this matters, I am using webwork 2.15, and here are the macros used:
loadMacros(
"PGstandard.pl",
"PGunion.pl",
"MathObjects.pl",
"PGcourse.pl",
"parserMultiAnswer.pl",
"PGchoicemacros.pl",
"PG.pl",
"PGbasicmacros.pl",
"PGchoicemacros.pl",
"PGanswermacros.pl",
"unionTables.pl",
);
Many thanks for your help!