464 Optional<Fraction> Simplex::computeRowOptimum(Direction direction,  in computeRowOptimum()
478   return Fraction(tableau(row, 1), tableau(row, 0));  in computeRowOptimum()
483 Optional<Fraction> Simplex::computeOptimum(Direction direction,  in computeOptimum()
490   Optional<Fraction> optimum = computeRowOptimum(direction, row);  in computeOptimum()
542     Optional<Fraction> minimum = computeRowOptimum(Direction::Down, row);  in detectRedundant()
543     if (!minimum || *minimum < Fraction(0, 1)) {  in detectRedundant()
562     Optional<Fraction> maybeMax = computeOptimum(Direction::Up, dir);  in isUnbounded()
566     Optional<Fraction> maybeMin = computeOptimum(Direction::Down, dir);  in isUnbounded()
711   Fraction computeWidthAndDuals(ArrayRef<int64_t> dir,  in computeWidthAndDuals()
717     Optional<Fraction> maybeWidth =  in computeWidthAndDuals()
862   const Fraction epsilon(3, 4);  in reduceBasis()
868   SmallVector<Fraction, 8> width;  in reduceBasis()
890   auto updateBasisWithUAndGetFCandidate = [&](unsigned i) -> Fraction {  in reduceBasis()
898       Fraction widthI[2];  in reduceBasis()
955     Fraction widthICandidate = updateBasisWithUAndGetFCandidate(i);  in reduceBasis()
1104   if (Optional<Fraction> maybeMin =  in computeIntegerBounds()
1111   if (Optional<Fraction> maybeMax =  in computeIntegerBounds()