un­der­over­lap – Po­si­tion dec­o­ra­tions over and un­der ex­pres­sions

The pack­age over­comes TeX's in­her­ent lim­i­ta­tions in com­mands that place dec­o­ra­tions (such as braces) at ar­birary po­si­tions over and un­der ex­pres­sions, over­lap­ping as nec­es­sary.