18 using Direction = Simplex::Direction;  typedef
167 bool signMatchesDirection(int64_t elem, Direction direction) {  in signMatchesDirection()
169   return direction == Direction::Up ? elem > 0 : elem < 0;  in signMatchesDirection()
172 Direction flippedDirection(Direction direction) {  in flippedDirection()
173   return direction == Direction::Up ? Direction::Down : Simplex::Direction::Up;  in flippedDirection()
856                                                 Direction direction) const {  in findPivot()
873   Direction newDirection =  in findPivot()
967     Optional<Pivot> maybePivot = findPivot(u.pos, Direction::Up);  in restoreRow()
1001                                          Direction direction,  in findPivotRow()
1163     if (Optional<unsigned> maybeRow = findPivotRow({}, Direction::Up, column)) {  in undoLastConstraint()
1166                    findPivotRow({}, Direction::Down, column)) {  in undoLastConstraint()
1311 MaybeOptimum<Fraction> Simplex::computeRowOptimum(Direction direction,  in computeRowOptimum()
1330 MaybeOptimum<Fraction> Simplex::computeOptimum(Direction direction,  in computeOptimum()
1341 MaybeOptimum<Fraction> Simplex::computeOptimum(Direction direction,  in computeOptimum()
1357   if (u.restricted && direction == Direction::Down &&  in computeOptimum()
1370   return computeOptimum(Direction::Up, con[constraintIndex]).isBounded();  in isBoundedAlongConstraint()
1414       Optional<unsigned> pivotRow = findPivotRow({}, Direction::Down, column);  in detectRedundant()
1423     MaybeOptimum<Fraction> minimum = computeRowOptimum(Direction::Down, row);  in detectRedundant()
1444     if (computeOptimum(Direction::Up, dir).isUnbounded())  in isUnbounded()
1447     if (computeOptimum(Direction::Down, dir).isUnbounded())  in isUnbounded()
1639         simplex.computeOptimum(Direction::Up, getCoeffsForDirection(dir));  in computeWidth()
1659         simplex.computeRowOptimum(Simplex::Direction::Up, row);  in computeWidthAndDuals()
2072       computeOptimum(Simplex::Direction::Down, coeffs).map(ceil));  in computeIntegerBounds()
2074       computeOptimum(Simplex::Direction::Up, coeffs).map(floor));  in computeIntegerBounds()
2145   MaybeOptimum<Fraction> minimum = computeOptimum(Direction::Down, coeffs);  in findIneqType()
2149   MaybeOptimum<Fraction> maximum = computeOptimum(Direction::Up, coeffs);  in findIneqType()
2172   MaybeOptimum<Fraction> minimum = computeOptimum(Direction::Down, coeffs);  in isRedundantEquality()
2173   MaybeOptimum<Fraction> maximum = computeOptimum(Direction::Up, coeffs);  in isRedundantEquality()