<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">I am trying to use the \sideset option to create a macro which prints one argument (say v) inside brackets, with a "subscript", on the left of the left bracket. The code for the macro is<DIV>**********************************************************************************</DIV><DIV>\newcommand{\matrepvec}[2]{\ensuremath{\sideset{_{#1}}{}{\operatorname{\lbrack #2\rbrack}}}}</DIV><DIV>*************************************************************************************</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>It gives me the effect I want, but has curious behavior with respect to variable #2: when I </DIV><DIV>invoke </DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>$\matrepvec{B}{\vec{v}}$</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>I get not v surmounted by an arrow, but v tilde (or something like it) inside the brackets. What is causing this?<BR><DIV> <SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px"><BR></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Zbigniew Nitecki</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Department of Mathematics</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Tufts University</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Medford, MA 02155</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px"><BR></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">telephones:</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Office<SPAN class="Apple-converted-space"><SPAN class="Apple-converted-tab"> <SPAN class="Apple-converted-space"> </SPAN></SPAN></SPAN>(617)627-3843</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Dept.<SPAN class="Apple-converted-space"><SPAN class="Apple-converted-tab"> <SPAN class="Apple-converted-space"> </SPAN></SPAN></SPAN>(617)627-3234</FONT></P><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Dept. fax<SPAN class="Apple-converted-space"><SPAN class="Apple-converted-tab"> <SPAN class="Apple-converted-space"> </SPAN></SPAN></SPAN>(617)627-3966</FONT></P><BR class="Apple-interchange-newline"></SPAN></SPAN> </DIV><BR></DIV></BODY></HTML>