.de EQ \" *** equation start
. if "\\n(.z"|e" .tm Line \\n(c. -- Nested .EQ request
.de EN \" *** equation end
. @q \" actual equation output
.de @q \" --- equation output
.sp \\n(esu \" output rest of preceeding text
.@C 2 \" .ev 2 may be jumbled from header
. in (\\n(.lu+\\n($iu-\\n(dlu)/2u
.if !"\\n(.z"" \!.ne \\n(_Qu
.ne \\n(_Qu+\n(.Vu \" keep it on one page
.if \n@>1 .tm --@e: _Q=\\n(_Q _q=\\n(_q nl=\\n(nl |p=\\*(|p
. sp (\\n(_Qu-\\n(.vu)/2u