diff --git a/source/operators/non_dominated_sorter/deductive_sort.cpp b/source/operators/non_dominated_sorter/deductive_sort.cpp
index 70a0e9ac..20d4a431 100644
--- a/source/operators/non_dominated_sorter/deductive_sort.cpp
+++ b/source/operators/non_dominated_sorter/deductive_sort.cpp
@@ -5,40 +5,48 @@
 #include "operon/core/individual.hpp"
 
 namespace Operon {
-
-    auto DeductiveSorter::Sort(Operon::Span<Operon::Individual const> pop, Operon::Scalar eps) const -> NondominatedSorterBase::Result
+    auto DeductiveSorter::Sort(Operon::Span<Operon::Individual const> pop, Operon::Scalar /*unused*/) const -> NondominatedSorterBase::Result
     {
         size_t n = 0; // total number of sorted solutions
         std::vector<std::vector<size_t>> fronts;
-        std::vector<bool> dominated(pop.size(), false);
-        std::vector<bool> sorted(pop.size(), false);
-        auto dominatedOrSorted = [&](size_t i) { return sorted[i] || dominated[i]; };
+
+        std::size_t constexpr d = std::numeric_limits<uint64_t>::digits;
+        auto const s = static_cast<int>(pop.size());
+        auto const nb = s / d + (s % d != 0);
+
+        std::vector<uint64_t> dominated(nb);
+        std::vector<uint64_t> sorted(nb);
+
+        auto set = [](auto&& range, auto i) { range[i / d] |= (1UL << (d - i % d));}; // set bit i
+        auto reset = [](auto&& range, auto i) { range[i / d] &= ~(1UL << (i % d)); }; // unset bit i
+        auto get = [](auto&& range, auto i) -> bool { return range[i / d] & (1UL << (d - i % d)); };
+
+        auto dominatedOrSorted = [&](std::size_t i) { return get(sorted, i) || get(dominated, i); };
 
         while (n < pop.size()) {
             std::vector<size_t> front;
 
             for (size_t i = 0; i < pop.size(); ++i) {
-                if (!dominatedOrSorted(i)) {
-                    for (size_t j = i + 1; j < pop.size(); ++j) {
-                        if (!dominatedOrSorted(j)) {
-                            auto const& lhs = pop[i];
-                            auto const& rhs = pop[j];
-                            auto res = ParetoDominance{}(lhs.Fitness, rhs.Fitness, eps);
-                            dominated[i] = (res == Dominance::Right);
-                            dominated[j] = (res == Dominance::Left);
-
-                            if (dominated[i]) {
-                                break;
-                            }
-                        }
-                    }
-
-                    if (!dominated[i]) {
-                        front.push_back(i);
-                        sorted[i] = true;
-                    }
+                if (dominatedOrSorted(i)) { continue; }
+
+                for (size_t j = i + 1; j < pop.size(); ++j) {
+                    if (dominatedOrSorted(j)) { continue; }
+
+                    auto const& lhs = pop[i];
+                    auto const& rhs = pop[j];
+                    auto res = ParetoDominance{}(lhs.Fitness, rhs.Fitness);
+                    if (res == Dominance::Right) { set(dominated, i); }
+                    if (res == Dominance::Left) { set(dominated, j); }
+
+                    if (get(dominated, i)) { break; }
+                }
+
+                if (!get(dominated, i)) {
+                    front.push_back(i);
+                    set(sorted, i);
                 }
             }
+
             std::fill(dominated.begin(), dominated.end(), 0UL);
             n += front.size();
             fronts.push_back(front);
diff --git a/source/operators/non_dominated_sorter/efficient_sort.cpp b/source/operators/non_dominated_sorter/efficient_sort.cpp
index dbfc1a40..f4f4f758 100644
--- a/source/operators/non_dominated_sorter/efficient_sort.cpp
+++ b/source/operators/non_dominated_sorter/efficient_sort.cpp
@@ -7,12 +7,12 @@
 namespace Operon {
 
     template<EfficientSortStrategy SearchStrategy>
-    inline auto EfficientSortImpl(Operon::Span<Operon::Individual const> pop, Operon::Scalar eps) -> NondominatedSorterBase::Result
+    inline auto EfficientSortImpl(Operon::Span<Operon::Individual const> pop, Operon::Scalar /*unused*/) -> NondominatedSorterBase::Result
     {
         // check if individual i is dominated by any individual in the front f
         auto dominated = [&](auto const& f, size_t i) {
             return std::any_of(f.rbegin(), f.rend(), [&](size_t j) {
-                return ParetoDominance{}(pop[j].Fitness, pop[i].Fitness, eps) == Dominance::Left;
+                return ParetoDominance{}(pop[j].Fitness, pop[i].Fitness) == Dominance::Left;
             });
         };
 
@@ -20,11 +20,9 @@ namespace Operon {
         for (size_t i = 0; i < pop.size(); ++i) {
             decltype(fronts)::iterator it;
             if constexpr (SearchStrategy == EfficientSortStrategy::Binary) { // binary search
-                it = std::partition_point(fronts.begin(), fronts.end(),
-                        [&](auto const& f) { return dominated(f, i); });
+                it = std::partition_point(fronts.begin(), fronts.end(), [&](auto const& f) { return dominated(f, i); });
             } else { // sequential search
-                it = std::find_if(fronts.begin(), fronts.end(),
-                        [&](auto const& f) { return !dominated(f, i); });
+                it = std::find_if(fronts.begin(), fronts.end(), [&](auto const& f) { return !dominated(f, i); });
             }
             if (it == fronts.end()) {
                 fronts.push_back({i});
diff --git a/source/operators/non_dominated_sorter/hierarchical_sort.cpp b/source/operators/non_dominated_sorter/hierarchical_sort.cpp
index acadd39f..63c50eef 100644
--- a/source/operators/non_dominated_sorter/hierarchical_sort.cpp
+++ b/source/operators/non_dominated_sorter/hierarchical_sort.cpp
@@ -8,7 +8,7 @@
 
 namespace Operon {
     auto
-    HierarchicalSorter::Sort(Operon::Span<Operon::Individual const> pop, Operon::Scalar eps) const -> NondominatedSorterBase::Result
+    HierarchicalSorter::Sort(Operon::Span<Operon::Individual const> pop, Operon::Scalar /*unused*/) const -> NondominatedSorterBase::Result
     {
         std::deque<size_t> q(pop.size());
         std::iota(q.begin(), q.end(), 0UL);
@@ -26,7 +26,7 @@ namespace Operon {
                 auto nonDominatedCount = 0UL;
                 while (q.size() > nonDominatedCount) {
                     auto qj = q.front(); q.pop_front();
-                    if (ParetoDominance{}(pop[q1].Fitness, pop[qj].Fitness, eps) == Dominance::None) {
+                    if (ParetoDominance{}(pop[q1].Fitness, pop[qj].Fitness) == Dominance::None) {
                         q.push_back(qj);
                         ++nonDominatedCount;
                     } else {
@@ -44,4 +44,3 @@ namespace Operon {
     }
 
 } // namespace Operon
-