cell->push_back(MathAtom(new InsetMathFrac(buf, InsetMathFrac::UNIT)));
cell->back().nucleus()->cell(0) = ar;
parse(cell->back().nucleus()->cell(1), FLAG_ITEM, mode);
cell->push_back(MathAtom(new InsetMathFrac(buf, InsetMathFrac::UNIT)));
cell->back().nucleus()->cell(0) = ar;
parse(cell->back().nucleus()->cell(1), FLAG_ITEM, mode);