diff --git a/untests/kari_ext_tests.cpp b/untests/kari_ext_tests.cpp
index 6d23a56..4a9527a 100644
--- a/untests/kari_ext_tests.cpp
+++ b/untests/kari_ext_tests.cpp
@@ -7,9 +7,66 @@
 #include <kari.hpp/kari_ext.hpp>
 #include "doctest/doctest.hpp"
 
-using namespace kari_hpp;
+#include "kari_tests.hpp"
+
+using namespace kari_hpp;
+using namespace kari_tests;
+
+TEST_CASE("kari_ext") {
+    SUBCASE("fid") {
+        REQUIRE(fid(box(10)).v() == 10);
+    }
+
+    SUBCASE("fconst") {
+        REQUIRE(fconst(box(10), 20).v() == 10);
+        {
+            auto b10 = fconst(box(10));
+            REQUIRE(b10(20).v() == 10);
+            REQUIRE(std::move(b10)(30).v() == 10);
+            REQUIRE(b10(20).v() == 100500);
+        }
+    }
+
+    SUBCASE("fflip") {
+        REQUIRE(fflip(curry(std::minus<>()))(10, 20) == 10);
+        REQUIRE(fflip(minus3_gl)(10,20,50) == -40);
+    }
+
+    SUBCASE("fpipe") {
+        using namespace underscore;
+        REQUIRE(fpipe(_+2, _*2, 4) == 12);
+        REQUIRE(((_+2) | (_*2) | 4) == 12);
+        REQUIRE((4 | (_+2) | (_*2)) == 12);
+    }
+
+    SUBCASE("fcompose") {
+        using namespace underscore;
+        REQUIRE(fcompose(_+2, _*2, 4) == 10);
+        REQUIRE((_+2) * (_*2) * 4 == 10);
+        REQUIRE(4 * (_+2) * (_*2) == 12);
+        {
+            const auto s3 = [](int v1, int v2, int v3){
+                return v1 + v2 + v3;
+            };
+            const auto c = curry(s3) * (_*2) * 10 * 20 * 30;
+            REQUIRE(c == 70);
+        }
+        {
+            // (. (+2)) (*2) $ 10 == 24
+            int i = fflip(fcompose)(_+2, _*2, 10);
+            int j = (_*(_+2))(_*2)(10);
+            REQUIRE(i == 24);
+            REQUIRE(j == 24);
+        }
+        {
+            // ((+2) .) (*2) $ 10 == 24
+            int i = fcompose(_+2)(_*2, 10);
+            int j = ((_+2) * _)(_*2)(10);
+            REQUIRE(i == 22);
+            REQUIRE(j == 22);
+        }
+    }
 
-TEST_CASE("kari_feature") {
     SUBCASE("underscore") {
         using namespace underscore;
         REQUIRE((-_)(40) == -40);
diff --git a/untests/kari_tests.cpp b/untests/kari_tests.cpp
index e7b89f2..4a71174 100644
--- a/untests/kari_tests.cpp
+++ b/untests/kari_tests.cpp
@@ -7,194 +7,15 @@
 #include <kari.hpp/kari.hpp>
 #include "doctest/doctest.hpp"
 
+#include "kari_tests.hpp"
+
+using namespace kari_hpp;
+using namespace kari_tests;
+
 #include <cstdio>
 #include <cstring>
 
-namespace
-{
-    const auto _42_tl = []() {
-        return 42;
-    };
-
-    const auto id_tl = [](int v) {
-        return v;
-    };
-
-    const auto minus2_tl = [](int v1, int v2) {
-        return v1 - v2;
-    };
-
-    const auto minus3_tl = [](int v1, int v2, int v3) {
-        return v1 - v2 - v3;
-    };
-
-    const auto minus4_tl = [](int v1, int v2, int v3, int v4) {
-        return v1 - v2 - v3 - v4;
-    };
-}
-
-namespace
-{
-    const auto id_gl = [](auto&& v) {
-        return v;
-    };
-
-    const auto minus2_gl = [](auto&& v1, auto&& v2) {
-        return v1 - v2;
-    };
-
-    const auto minus3_gl = [](auto&& v1, auto&& v2, auto&& v3) {
-        return v1 - v2 - v3;
-    };
-
-    const auto minus4_gl = [](auto&& v1, auto&& v2, auto&& v3, auto&& v4) {
-        return v1 - v2 - v3 - v4;
-    };
-}
-
-namespace
-{
-    struct id_gf {
-        template < typename T >
-        constexpr auto operator()(T&& v) const {
-            return v;
-        }
-    };
-
-    struct minus2_gf {
-        template < typename T1, typename T2 >
-        constexpr auto operator()(T1&& v1, T2&& v2) const {
-            return v1 - v2;
-        }
-    };
-
-    struct minus3_gf {
-        template < typename T1, typename T2, typename T3 >
-        constexpr auto operator()(T1&& v1, T2&& v2, T3&& v3) const {
-            return v1 - v2 - v3;
-        }
-    };
-
-    struct plusV_gf {
-        template < typename A >
-        constexpr decltype(auto) operator()(A&& a) const {
-            return std::forward<A>(a);
-        }
-
-        template < typename A, typename B >
-        constexpr decltype(auto) operator()(A&& a, B&& b) const {
-            return std::forward<A>(a) + std::forward<B>(b);
-        }
-
-        template < typename A, typename B, typename... Cs >
-        constexpr decltype(auto) operator()(A&& a, B&& b, Cs&&... cs) const {
-            return (*this)(
-                (*this)(std::forward<A>(a), std::forward<B>(b)),
-                std::forward<Cs>(cs)...);
-        }
-    };
-}
-
-namespace
-{
-    struct box {
-        box(int v) : v_(v) {}
-        ~box() {
-            v_ = 100500;
-        }
-
-        box(box&& o) : v_(o.v_) {
-            o.v_ = 100500;
-            ++moveCount_;
-        }
-
-        box(const box& o) : v_(o.v_) {
-            ++copyCount_;
-        }
-
-        box& operator=(box&& o) = delete;
-        box& operator=(const box&) = delete;
-
-        int v() const { return v_; }
-
-        int addV(int add) {
-            v_ += add;
-            return v_;
-        }
-
-        static void resetCounters() {
-            moveCount_ = 0;
-            copyCount_ = 0;
-        }
-
-        static int moveCount() {
-            return moveCount_;
-        }
-
-        static int copyCount() {
-            return copyCount_;
-        }
-    private:
-        int v_;
-        static int moveCount_;
-        static int copyCount_;
-    };
-
-    int box::moveCount_;
-    int box::copyCount_;
-
-    static box operator+(const box& lhs, const box& rhs) {
-        return box(lhs.v() + rhs.v());
-    }
-
-    static box operator-(const box& lhs, const box& rhs) {
-        return box(lhs.v() - rhs.v());
-    }
-}
-
-namespace
-{
-    struct box_without_move {
-        box_without_move(int v) : v_(v) {}
-        ~box_without_move() {
-            v_ = 100500;
-        }
-
-        box_without_move(const box_without_move& o) : v_(o.v_) {
-            ++copyCount_;
-        }
-
-        box_without_move& operator=(const box_without_move&) = delete;
-
-        int v() const { return v_; }
-
-        int addV(int add) {
-            v_ += add;
-            return v_;
-        }
-
-        static void resetCounters() {
-            copyCount_ = 0;
-        }
-
-        static int copyCount() {
-            return copyCount_;
-        }
-    private:
-        int v_;
-        static int copyCount_;
-    };
-
-    int box_without_move::copyCount_;
-
-    static box_without_move operator+(const box_without_move& lhs, const box_without_move& rhs) {
-        return box_without_move(lhs.v() + rhs.v());
-    }
-}
-
-using namespace kari_hpp;
-
-TEST_CASE("kari_feature") {
+TEST_CASE("kari") {
     SUBCASE("ref_functor") {
         REQUIRE(curry(minus3_gf())(1,2,3) == -4);
         {
@@ -232,7 +53,7 @@ TEST_CASE("kari_feature") {
     }
     SUBCASE("move_vs_copy") {
         {
-            box::resetCounters();
+            box<>::resetCounters();
             const auto b1 = box(1);
             const auto b2 = box(2);
             const auto b3 = box(3);
@@ -241,11 +62,11 @@ TEST_CASE("kari_feature") {
             curry([](auto&& v1, auto&& v2, auto&& v3, auto&& v4, auto&& v5){
                 return v1 + v2 + v3 + v4 + v5;
             })(std::move(b1))(std::move(b2))(std::move(b3))(std::move(b4))(std::move(b5));
-            REQUIRE(box::moveCount() == 25);
-            REQUIRE(box::copyCount() == 5);
+            REQUIRE(box<>::moveCount() == 25);
+            REQUIRE(box<>::copyCount() == 5);
         }
         {
-            box::resetCounters();
+            box<>::resetCounters();
             auto b1 = box(1);
             auto b2 = box(2);
             auto b3 = box(3);
@@ -254,35 +75,35 @@ TEST_CASE("kari_feature") {
             curry([](auto&& v1, auto&& v2, auto&& v3, auto&& v4, auto&& v5){
                 return v1 + v2 + v3 + v4 + v5;
             })(std::move(b1))(std::move(b2))(std::move(b3))(std::move(b4))(std::move(b5));
-            REQUIRE(box::moveCount() == 30);
-            REQUIRE(box::copyCount() == 0);
+            REQUIRE(box<>::moveCount() == 30);
+            REQUIRE(box<>::copyCount() == 0);
         }
         {
-            box::resetCounters();
+            box<>::resetCounters();
             curry([](auto&& v1, auto&& v2, auto&& v3, auto&& v4, auto&& v5){
                 return v1 + v2 + v3 + v4 + v5;
             })(box(1))(box(2))(box(3))(box(4))(box(5));
-            REQUIRE(box::moveCount() == 30);
-            REQUIRE(box::copyCount() == 0);
+            REQUIRE(box<>::moveCount() == 30);
+            REQUIRE(box<>::copyCount() == 0);
         }
         {
-            box::resetCounters();
+            box<>::resetCounters();
             curry([](auto&& v1, auto&& v2, auto&& v3, auto&& v4, auto&& v5){
                 return v1 + v2 + v3 + v4 + v5;
             })(box(1),box(2))(box(3),box(4))(box(5));
-            REQUIRE(box::moveCount() == 30);
-            REQUIRE(box::copyCount() == 0);
+            REQUIRE(box<>::moveCount() == 30);
+            REQUIRE(box<>::copyCount() == 0);
         }
         {
-            box::resetCounters();
+            box<>::resetCounters();
             curry([](auto&& v1, auto&& v2, auto&& v3, auto&& v4, auto&& v5){
                 return v1 + v2 + v3 + v4 + v5;
             })(box(1),box(2),box(3),box(4),box(5));
-            REQUIRE(box::moveCount() == 30);
-            REQUIRE(box::copyCount() == 0);
+            REQUIRE(box<>::moveCount() == 30);
+            REQUIRE(box<>::copyCount() == 0);
         }
         {
-            box::resetCounters();
+            box<>::resetCounters();
             const auto c0 = curry([](auto&& v1, auto&& v2, auto&& v3, auto&& v4, auto&& v5){
                 return v1 + v2 + v3 + v4 + v5;
             });
@@ -292,11 +113,11 @@ TEST_CASE("kari_feature") {
             const auto c4 = c3(box(4));
             const auto c5 = c4(box(5));
             REQUIRE(c5.v() == 15);
-            REQUIRE(box::moveCount() == 30);
-            REQUIRE(box::copyCount() == 10);
+            REQUIRE(box<>::moveCount() == 30);
+            REQUIRE(box<>::copyCount() == 10);
         }
         {
-            box_without_move::resetCounters();
+            box_without_move<>::resetCounters();
             const auto c0 = curry([](auto&& v1, auto&& v2, auto&& v3, auto&& v4, auto&& v5){
                 return v1 + v2 + v3 + v4 + v5;
             });
@@ -306,16 +127,16 @@ TEST_CASE("kari_feature") {
             const auto c4 = c3(box_without_move(4));
             const auto c5 = c4(box_without_move(5));
             REQUIRE(c5.v() == 15);
-            REQUIRE(box_without_move::copyCount() == 40);
+            REQUIRE(box_without_move<>::copyCount() == 40);
         }
         {
-            box::resetCounters();
+            box<>::resetCounters();
             curryV(plusV_gf())(box(1),box(2),box(3),box(4),box(5))();
-            REQUIRE(box::moveCount() == 35);
-            REQUIRE(box::copyCount() == 0);
+            REQUIRE(box<>::moveCount() == 35);
+            REQUIRE(box<>::copyCount() == 0);
         }
         {
-            box::resetCounters();
+            box<>::resetCounters();
             const auto c0 = curryV(plusV_gf());
             const auto c1 = c0(box(1));
             const auto c2 = c1(box(2));
@@ -323,8 +144,8 @@ TEST_CASE("kari_feature") {
             const auto c4 = c3(box(4));
             const auto c5 = c4(box(5));
             REQUIRE(c5().v() == 15);
-            REQUIRE(box::moveCount() == 35);
-            REQUIRE(box::copyCount() == 15);
+            REQUIRE(box<>::moveCount() == 35);
+            REQUIRE(box<>::copyCount() == 15);
         }
     }
     SUBCASE("persistent") {
@@ -352,7 +173,7 @@ TEST_CASE("kari_feature") {
     }
 }
 
-TEST_CASE("kari") {
+TEST_CASE("kari/curry") {
     SUBCASE("arity/min_arity") {
         REQUIRE(curry(minus3_gl).min_arity() == 0);
         REQUIRE(curryV(plusV_gf()).min_arity() == std::numeric_limits<std::size_t>::max());
@@ -549,14 +370,14 @@ TEST_CASE("kari") {
     }
     SUBCASE("member_functions") {
         {
-            auto c0 = curry(&box::addV);
-            auto c1 = curry(&box::v);
+            auto c0 = curry(&box<>::addV);
+            auto c1 = curry(&box<>::v);
             REQUIRE(c0(box(10), 2) == 12);
             REQUIRE(c1(box(12)) == 12);
         }
         {
-            auto c0 = curry(&box::addV);
-            auto c1 = curry(&box::v);
+            auto c0 = curry(&box<>::addV);
+            auto c1 = curry(&box<>::v);
 
             auto b1 = box(10);
             const auto b2 = box(10);
@@ -572,7 +393,7 @@ TEST_CASE("kari") {
         }
     }
     SUBCASE("member_objects") {
-        struct box2 : box {
+        struct box2 : box<> {
             box2(int v) : box(v), ov(v) {}
             int ov;
         };
diff --git a/untests/kari_tests.hpp b/untests/kari_tests.hpp
new file mode 100644
index 0000000..00e1231
--- /dev/null
+++ b/untests/kari_tests.hpp
@@ -0,0 +1,195 @@
+/*******************************************************************************
+ * This file is part of the "https://github.com/BlackMATov/kari.hpp"
+ * For conditions of distribution and use, see copyright notice in LICENSE.md
+ * Copyright (C) 2017-2020, by Matvey Cherevko (blackmatov@gmail.com)
+ ******************************************************************************/
+
+#pragma once
+
+namespace kari_tests
+{
+    inline constexpr auto _42_tl = []() {
+        return 42;
+    };
+
+    inline constexpr auto id_tl = [](int v) {
+        return v;
+    };
+
+    inline constexpr auto minus2_tl = [](int v1, int v2) {
+        return v1 - v2;
+    };
+
+    inline constexpr auto minus3_tl = [](int v1, int v2, int v3) {
+        return v1 - v2 - v3;
+    };
+
+    inline constexpr auto minus4_tl = [](int v1, int v2, int v3, int v4) {
+        return v1 - v2 - v3 - v4;
+    };
+
+    inline constexpr auto id_gl = [](auto&& v) {
+        return v;
+    };
+
+    inline constexpr auto minus2_gl = [](auto&& v1, auto&& v2) {
+        return v1 - v2;
+    };
+
+    inline constexpr auto minus3_gl = [](auto&& v1, auto&& v2, auto&& v3) {
+        return v1 - v2 - v3;
+    };
+
+    inline constexpr auto minus4_gl = [](auto&& v1, auto&& v2, auto&& v3, auto&& v4) {
+        return v1 - v2 - v3 - v4;
+    };
+}
+
+namespace kari_tests
+{
+    struct id_gf {
+        template < typename T >
+        constexpr auto operator()(T&& v) const {
+            return v;
+        }
+    };
+
+    struct minus2_gf {
+        template < typename T1, typename T2 >
+        constexpr auto operator()(T1&& v1, T2&& v2) const {
+            return v1 - v2;
+        }
+    };
+
+    struct minus3_gf {
+        template < typename T1, typename T2, typename T3 >
+        constexpr auto operator()(T1&& v1, T2&& v2, T3&& v3) const {
+            return v1 - v2 - v3;
+        }
+    };
+
+    struct plusV_gf {
+        template < typename A >
+        constexpr decltype(auto) operator()(A&& a) const {
+            return std::forward<A>(a);
+        }
+
+        template < typename A, typename B >
+        constexpr decltype(auto) operator()(A&& a, B&& b) const {
+            return std::forward<A>(a) + std::forward<B>(b);
+        }
+
+        template < typename A, typename B, typename... Cs >
+        constexpr decltype(auto) operator()(A&& a, B&& b, Cs&&... cs) const {
+            return (*this)(
+                (*this)(std::forward<A>(a), std::forward<B>(b)),
+                std::forward<Cs>(cs)...);
+        }
+    };
+}
+
+namespace kari_tests
+{
+    template < typename = void >
+    struct box {
+        box(int v) : v_(v) {}
+        ~box() {
+            v_ = 100500;
+        }
+
+        box(box&& o) : v_(o.v_) {
+            o.v_ = 100500;
+            ++moveCount_;
+        }
+
+        box(const box& o) : v_(o.v_) {
+            ++copyCount_;
+        }
+
+        box& operator=(box&& o) = delete;
+        box& operator=(const box&) = delete;
+
+        int v() const { return v_; }
+
+        int addV(int add) {
+            v_ += add;
+            return v_;
+        }
+
+        static void resetCounters() {
+            moveCount_ = 0;
+            copyCount_ = 0;
+        }
+
+        static int moveCount() {
+            return moveCount_;
+        }
+
+        static int copyCount() {
+            return copyCount_;
+        }
+    private:
+        int v_;
+        static int moveCount_;
+        static int copyCount_;
+    };
+
+    template < typename T >
+    int box<T>::moveCount_;
+
+    template < typename T >
+    int box<T>::copyCount_;
+
+    template < typename T >
+    inline box<T> operator+(const box<T>& lhs, const box<T>& rhs) {
+        return box(lhs.v() + rhs.v());
+    }
+
+    template < typename T >
+    inline box<T> operator-(const box<T>& lhs, const box<T>& rhs) {
+        return box(lhs.v() - rhs.v());
+    }
+}
+
+namespace kari_tests
+{
+    template < typename = void >
+    struct box_without_move {
+        box_without_move(int v) : v_(v) {}
+        ~box_without_move() {
+            v_ = 100500;
+        }
+
+        box_without_move(const box_without_move& o) : v_(o.v_) {
+            ++copyCount_;
+        }
+
+        box_without_move& operator=(const box_without_move&) = delete;
+
+        int v() const { return v_; }
+
+        int addV(int add) {
+            v_ += add;
+            return v_;
+        }
+
+        static void resetCounters() {
+            copyCount_ = 0;
+        }
+
+        static int copyCount() {
+            return copyCount_;
+        }
+    private:
+        int v_;
+        static int copyCount_;
+    };
+
+    template < typename T >
+    int box_without_move<T>::copyCount_;
+
+    template < typename T >
+    inline box_without_move<T> operator+(const box_without_move<T>& lhs, const box_without_move<T>& rhs) {
+        return box_without_move(lhs.v() + rhs.v());
+    }
+}