diff --git a/CMakeLists.txt b/CMakeLists.txt
index 90de0e6..0a92a1d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 3.10)
 project(toddcox-faster)
 
+set(CMAKE_CXX_STANDARD 17)
+
 option(TC_BUILD_EXAMPLE "Build example executables" OFF)
 
 add_subdirectory(ext)
diff --git a/include/tc/core.hpp b/include/tc/core.hpp
index 4b6ed0d..7505211 100644
--- a/include/tc/core.hpp
+++ b/include/tc/core.hpp
@@ -1,5 +1,4 @@
 #pragma once
 
-#include "tc/core/rel.hpp"
 #include "tc/core/group.hpp"
 #include "tc/core/solver.hpp"
diff --git a/include/tc/core/group.hpp b/include/tc/core/group.hpp
index cc8629c..4e56033 100644
--- a/include/tc/core/group.hpp
+++ b/include/tc/core/group.hpp
@@ -7,8 +7,6 @@
 #include <memory>
 #include <queue>
 
-#include "rel.hpp"
-
 #include <Eigen/Eigen>
 #include <iostream>
 
@@ -65,16 +63,6 @@ namespace tc {
         typename Matrix::Scalar operator()(int a, int b) const {
             return _mults(a, b);
         }
-
-        [[nodiscard]] std::vector<Rel> get_rels() const {
-            std::vector<Rel> res;
-            for (int i = 0; i < Rank - 1; ++i) {
-                for (int j = i + 1; j < Rank; ++j) {
-                    res.emplace_back(i, j, _mults(i, j));
-                }
-            }
-            return res;
-        }
     };
 
     template<unsigned int GR, unsigned int HR>
@@ -121,12 +109,4 @@ namespace tc {
 
         return res;
     }
-
-//    Group operator*(const Group &g, const Group &h) {
-//        return product(g, h);
-//    }
-//
-//    Group operator^(const Group &g, int p) {
-//        return power(g, p);
-//    }
 }
diff --git a/include/tc/core/rel.hpp b/include/tc/core/rel.hpp
deleted file mode 100644
index d064428..0000000
--- a/include/tc/core/rel.hpp
+++ /dev/null
@@ -1,20 +0,0 @@
-#pragma once
-
-#include <array>
-
-struct Rel {
-    std::array<int, 2> gens;
-    int mult;
-
-    Rel() = default;
-
-    Rel(const Rel &) = default;
-
-    Rel(int a, int b, int m)
-        : gens({a, b}), mult(m) {
-    }
-
-    [[nodiscard]] Rel shift(int off) const {
-        return Rel(gens[0] + off, gens[1] + off, mult);
-    }
-};
diff --git a/include/tc/core/solver.hpp b/include/tc/core/solver.hpp
index 356857b..e9ff640 100644
--- a/include/tc/core/solver.hpp
+++ b/include/tc/core/solver.hpp
@@ -105,11 +105,13 @@ namespace {
     struct Table {
     private:
     public:
-        Rel rel;
+        int i, j, mult;
+
         std::vector<Row> rows;
 
     public:
-        explicit Table(const Rel &rel) : rel(rel) {
+        explicit Table(int i, int j, int mult) :
+            i(i), j(j), mult(mult) {
         }
     };
 
@@ -159,13 +161,13 @@ namespace {
 
     public:
         explicit Tables(const tc::Group<Rank> &group) {
-            const auto &rels = group.get_rels();
-            for (int i = 0; i < Rels; ++i) {
-                const auto &rel = rels[i];
-                auto table = std::make_shared<Table>(rel);
-                tables[i] = table;
-                deps[rel.gens[0]].push_back(table);
-                deps[rel.gens[1]].push_back(table);
+            for (int i = 0, irel = 0; i < Rank - 1; ++i) {
+                for (int j = i + 1; j < Rank; ++j, ++irel) {
+                    auto table = std::make_shared<Table>(i, j, group(i, j));
+                    tables[irel] = table;
+                    deps[i].push_back(table);
+                    deps[j].push_back(table);
+                }
             }
         }
 
@@ -178,12 +180,11 @@ namespace {
 
         void initialize(int target, const tc::Cosets<Rank> &cosets) {
             for (auto &table: tables) {
-                const Rel &rel = table->rel;
                 Row &row = table->rows[target];
 
                 if (row.lst == nullptr) {
-                    if (cosets.get(target, rel.gens[0]) != target and
-                        cosets.get(target, rel.gens[1]) != target) {
+                    if (cosets.get(target, table->i) != target and
+                        cosets.get(target, table->j) != target) {
                         row.lst = alloc();
                         row.gnr = 0;
                     } else {
@@ -212,7 +213,6 @@ namespace {
             for (auto &table: deps[gen]) {
                 Row &target_row = table->rows[target];
                 Row &coset_row = table->rows[coset];
-                const Rel &rel = table->rel;
 
                 if (target_row.lst == nullptr) {
                     target_row.lst = coset_row.lst;
@@ -222,16 +222,16 @@ namespace {
                         target_row.gnr -= 2;
                     }
 
-                    if (target_row.gnr == rel.mult) {
+                    if (target_row.gnr == table->mult) {
                         // forward learn
                         int lst = *target_row.lst;
-                        int gen_ = rel.gens[rel.gens[0] == gen];
+                        int gen_ = (table->i == gen) ? table->j : table->i;
                         facts.push(lst * Rank + gen_);
-                    } else if (target_row.gnr == -rel.mult) {
+                    } else if (target_row.gnr == -table->mult) {
                         // stationary learn
-                        int gen_ = rel.gens[rel.gens[0] == gen];
+                        int gen_ = (table->i == gen) ? table->j : table->i;
                         facts.push(target * Rank + gen_);
-                    } else if (target_row.gnr == rel.mult - 1) {
+                    } else if (target_row.gnr == table->mult - 1) {
                         // determined family
                         *target_row.lst = target;
                     }