diff --git a/config/default.json b/config/default.json
index 9ce4b3c..1b714c4 100644
--- a/config/default.json
+++ b/config/default.json
@@ -1,74 +1,74 @@
 {
     "containers": {
       "id": {
           "implementations": "containers_impl",
           "linkedlist": "linkedlist"
       }, 
       
       "impl": {
         "solid": "solid",
         "onthefly": "onthefly"
       }
     },
     
     "logging": {
       "id": "logging"
     },
     
     "function-entry": "entry",
     
     "transcend": {
       "bindings" : {
         "variable": "bind",
         "function": "bind_func",
         "scope": "bind_scope",
         "function_demand" : "bind_function_demand",
         "scope_decision": "bind_scope_decision"
       },
       
       "context" : {
         "decisions":{
             "dependent": "resolution_dependency"
         }
       }, 
       
       "nonevalue": "nonevalue",
       "ret": {
         "symbol": "retv",
         "tag": "ret"
       } 
     },
         
     "tests": { 
       "template": "troubleshooting",
       
       "templates": {
-        "troubleshooting":"-Latex.*:*.Doc_*",
+        "troubleshooting":"Example.Example1",
         "documentation":"Modules.Doc_*:Modules_API.Doc_*:Interpretation.Doc_*:AST.Doc_*:Loop.Doc_*:LateReasoning.Doc_*:Latex.Doc_*:Polymorphs.Doc_*:Transcend.Doc_*:ASTCorrespondence.Doc_*:Virtualization.Doc_*:Exploitation.Doc_*:Communication.Doc_*:Introduction.*",
         "default": "*",
         "ast": "AST.*",
         "effects": "Effects.*",
         "basic": "Attachments.*", 
         "compilation": "Compilation.*",
         "communication": "Communication.*",
         "cfa": "CFA.*",
         "containers": "Containers.*",
         "dfa": "DFA.*",
         "diagnostic": "Diagnostic.*",
         "dsl": "Association.*:Interpretation.*",
         "exploitation": "Exploitation.*",
         "ExpressionSerializer": "ExpressionSerializer.*",
         "externc": "InterfaceExternC.*",
         "loops": "Loop.*",
         "latereasoning": "LateReasoning.*",
         "latex": "Latex.*",
         "modules": "Modules.*",
         "polymorphs": "Polymorphs.*",
         "intrinsic-query": "Types.SlaveTypes*:Association.TypedQuery*",
         "types": "Types.*", 
         "virtualization": "Virtualization.*",      
         "vendorsAPI/clang": "ClangAPI.*",
         "vendorsAPI/xml2": "libxml2.*"
       }
     }
 }
diff --git a/cpp/tests/CMakeLists.txt b/cpp/tests/CMakeLists.txt
index 8d6a2e4..2890e4b 100644
--- a/cpp/tests/CMakeLists.txt
+++ b/cpp/tests/CMakeLists.txt
@@ -1,59 +1,60 @@
 cmake_minimum_required(VERSION 2.8.11)
 project(xreate-tests)
 
 find_package(GTest REQUIRED)
 INCLUDE_DIRECTORIES(${GTEST_INCLUDE_DIRS})
 INCLUDE_DIRECTORIES("/usr/include/libxml2")
 INCLUDE_DIRECTORIES($<TARGET_PROPERTY:xreate,INCLUDE_DIRECTORIES>)
 
 
 #       TESTS
 #=========================
 FIND_PACKAGE (LLVM REQUIRED)
 message("LLVM_LIBRARY_DIRS: " ${LLVM_LIBRARY_DIRS})
 link_directories(${LLVM_LIBRARY_DIRS})
 
 set (LIBCLASP_PATH ${POTASSCO_PATH}/build/debug)
 link_directories(${LIBCLASP_PATH})
 
 #aux_source_directory(. TEST_FILES)
 set(TEST_FILES
     introduction.cpp
+    unit-test-example.cpp
     transcend-ast.cpp
     supplemental/docutils
     latetranscend.cpp
     cfa.cpp
     latex.cpp
     polymorph.cpp
     transcend.cpp
     virtualization.cpp
     exploitation.cpp
     effects-communication.cpp
     association.cpp
     main.cpp
     modules.cpp
     attachments.cpp
     ast.cpp
     dfa.cpp
     compilation.cpp
     ExpressionSerializer.cpp
     externc.cpp
     types.cpp
     #vendorsAPI/clangAPI.cpp
     #vendorsAPI/xml2.cpp
     #vendorsAPI/json.cpp
     
     containers.cpp
     interpretation.cpp
     loops.cpp
 
     #supplemental/versions-algorithm-data_dependency.cpp
     effects-versions.cpp
 )
     
 add_executable(${PROJECT_NAME} ${TEST_FILES})
 target_link_libraries(${PROJECT_NAME} xreate ${GTEST_LIBRARIES} pthread xml2 gcov)
 
 add_custom_target (coverage
     COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/src/code-coverage.sh
     WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
diff --git a/cpp/tests/latex.cpp b/cpp/tests/latex.cpp
index a8d3cec..77db129 100644
--- a/cpp/tests/latex.cpp
+++ b/cpp/tests/latex.cpp
@@ -1,334 +1,328 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/
  *
  * Author: pgess <v.melnychenko@xreate.org>
  * Created on June 25, 2018, 5:42 PM
  *
  * \file    latex.cpp
  * \brief   Testing of latex
  */
 
 #include "xreatemanager.h"
 #include "pass/compilepass.h"
 #include "transcendlayer.h"
 #include "query/latex.h"
 #include "compilation/latex.h"
 #include "aux/xreatemanager-decorators.h"
 #include "compilation/scopedecorators.h"
 #include "llvmlayer.h"
 #include "supplemental/docutils.h"
 
 #include <boost/format.hpp>
 #include <gtest/gtest.h>
 
 using namespace xreate::latex;
 using namespace xreate::latereasoning;
 using namespace xreate::compilation;
 using namespace xreate;
 using namespace std;
 
 TEST(Latex, Script_NestedScopePropagation_1) {
     std::string program =
     R"CODE(
         import raw("scripts/cfa/context.lp").
         fn = function:: int; entry
         {
             context:: test1.
             if(1==11)::int {2} else {3}
         }
     )CODE";
 
     std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
 
     CodeScope* blockTrue = man->root->findFunction("fn")->getEntryScope()->getBody().blocks.front();
     auto blockTrueP = man->transcend->pack(blockTrue);
     boost::format formatAlias("alias(%1%, %2%).");
     man->transcend->addRawScript((formatAlias % blockTrueP % "block1").str());
     man->transcend->addRawScript(
         R"SCRIPT(
         success1:- bind_scope(Block1, test1, strong); alias(Block1, block1).
     )SCRIPT");
     man->analyse();
 
     ASSERT_EQ(1, man->transcend->query("success1").size());
 }
 
 TEST(Latex, Script_DemAndDecision_1) {
     std::string program =
         R"CODE(
         import raw("scripts/cfa/context.lp").
 
         a = function:: int
         {
             context:: forC(a).
             c()
         }
 
         b = function:: int
         {
             context:: forC(b).
             c()
         }
 
         c = function:: int {0}
 
         main = function:: int; entry
         {
             a() + b()
         }
     )CODE";
 
     std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
 
     CodeScope* blockC = man->root->findFunction("c")->getEntryScope();
     auto blockCP = man->transcend->pack(blockC);
     boost::format formatAlias("alias(%1%, %2%).");
     man->transcend->addRawScript((formatAlias % blockCP % "blockC").str());
     man->transcend->addRawScript(
         R"SCRIPT(
         latex_scope_demand(BlockC, forC):- alias(BlockC, blockC).
         latex_registered_subjects(forC, Variant):- bind_scope(_, Variant, strong); Variant = forC(_).
         )SCRIPT");
     man->analyse();
 
     ASSERT_EQ(1, man->transcend->query("latex_fn_demand").size());
     ASSERT_EQ(2, man->transcend->query("latex_decision").size());
 }
 
 TEST(Latex, LatexQuery_getFnDemand_1){
     std::string program =
         R"CODE(
         import raw("scripts/cfa/context.lp").
         main = function:: int; entry
         {
             context:: alias(blockMain).
             0
         }
         )CODE";
     
     std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
     man->transcend->addRawScript(
         R"SCRIPT(
         latex_scope_demand(BlockC, forC):- bind_scope(BlockC, alias(blockMain), strong).
         latex_registered_subjects(forC, decisionSome).
         )SCRIPT");
     
     LatexQuery* query = new LatexQuery();
     man->transcend->registerQuery(query, QueryId::LatexQuery);
     man->analyse();
     
     Demand demand = query->getFnDemand("main");
     ASSERT_EQ(1, demand.size());
     ASSERT_STREQ("forC", demand.front().c_str());
 }
 
 TEST(Latex, LatexQuery_getDecision_static_1){
     std::string program =
     R"CODE(
     import raw("scripts/cfa/context.lp").
         a = function:: int {context::decisionSome. c()}
         b = function:: int {c()}
         c = function:: int {context:: alias(blockC). 0}
     )CODE";
     
     std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
     man->transcend->addRawScript(
         R"SCRIPT(
         latex_scope_demand(BlockC, forC):- bind_scope(BlockC, alias(blockC), strong).
         latex_registered_subjects(forC, decisionSome).
         )SCRIPT");
     
     LatexQuery* query = new LatexQuery();
     man->transcend->registerQuery(query, QueryId::LatexQuery);
     man->analyse();
     
     LateAnnotation decisionLA = query->getDecision("forC", man->root->findFunction("a")->getEntryScope());
     auto decisionGS = decisionLA.select({}, man->root, man->transcend);
     ASSERT_TRUE(decisionGS);
     
     decisionGS->print(cout);
     cout << endl;
     auto decisionTuple = man->transcend->parse<Gringo::Symbol, Gringo::Symbol, string>(*decisionGS);
     string decision = get<2>(decisionTuple);
     ASSERT_STREQ("decisionSome", decision.c_str());
 }
   
 TEST(Latex, Compilation_1) {
     std::string program =
         R"CODE(
 
         a = function:: int
         {0}
 
         main = function:: int; entry
         {
             a()
         }
         )CODE";
 
     string script =
         R"SCRIPT(
             latex_fn_demand(%1%, subject1).
             latex_decision(%2%, subject1, 5).
             latex_registered_subjects(subject1, 1).
             latex_registered_subjects(subject1, 5).
         )SCRIPT";
 
     typedef LatexBruteFunctionDecorator<compilation::BasicFunctionUnit> FnImpl;
     typedef LatexBruteScopeDecorator<compilation::CachedScopeDecorator<compilation::BasicCodeScopeUnit>> ScopeImpl;
 
     std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
     ScopePacked scopeMainP = man->transcend->pack(man->root->findFunction("main")->getEntryScope());
     boost::format format(script);
     man->transcend->addRawScript((format % "a" % scopeMainP).str());
     man->transcend->registerQuery(new LatexQuery(), QueryId::LatexQuery);
     man->analyse();
 
     std::unique_ptr<CompilePass> compiler(new compilation::CompilePassCustomDecorators<FnImpl, ScopeImpl>(man.get()));
     compiler->run();
     man->llvm->initJit();
     int(*fnMain)() = (int(*)())man->llvm->getFunctionPointer(compiler->getEntryFunction());
     ASSERT_EQ(0, fnMain());
 }
 
 //
 //TEST(Latex, Full1) {
 //    std::string program =
 //        R"CODE(
 //            import raw("scripts/cfa/context.lp").
 //
 //            a = function:: int
 //            {
 //                context:: forC(a).
 //                c()
 //            }
 //
 //            b = function:: int
 //            {
 //                context:: forC(b).
 //                c()
 //            }
 //
 //            c = function:: int {0}
 //
 //            main = function:: int; entry
 //            {
 //                a() + b()
 //            }
 //        )CODE";
 //
 //    string script =
 //        R"SCRIPT(
 //            alias(%1%, scopeC).
 //            latex_scope_demand(ScopeC, forC) :- alias(ScopeC, scopeC).
 //            latex_registered_subjects(forC, forC(a)).
 //            latex_registered_subjects(forC, forC(b)).
 //        )SCRIPT";
 //
 //    typedef LatexBruteFunctionDecorator<compilation::BasicFunctionUnit> FnImpl;
 //    typedef LatexBruteScopeDecorator<compilation::CachedScopeDecorator<compilation::BasicCodeScopeUnit>> ScopeImpl;
 //
 //    std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
 //    ScopePacked scopeMainP = man->transcend->pack(man->root->findFunction("main")->getEntryScope());
 //    auto scopeCP = man->transcend->pack(man->root->findFunction("c")->getEntryScope());
 //    boost::format format(script);
 //    man->transcend->addRawScript((format %scopeCP).str());
 //    man->transcend->registerQuery(new LatexQuery(), QueryId::LatexQuery);
 //    man->analyse();
 //
 //    std::unique_ptr<CompilePass> compiler(new compilation::CompilePassCustomDecorators<FnImpl, ScopeImpl>(man.get()));
 //    compiler->run();
 //    man->llvm->print();
 //}
 //
 TEST(Latex, Compilation_TransitFn1){
     std::string program =
         R"CODE(
             import raw("scripts/cfa/context.lp").
 
             branchA = function:: int
             {
                 context:: sink_a.
                 fnTransit()
             }
 
             branchB = function:: int
             {
                 context:: sink_b.
                 fnTransit()
             }
 
             fnSink = function:: int {0}
             fnTransit = function:: int {fnSink()}
 
             main = function:: int; entry
             {
                 branchA() + branchB()
             }
         )CODE";
 
     string script =
 R"SCRIPT(
     alias(scopeSink, %1%).
     latex_scope_demand(ScopeSink, sink):- alias(scopeSink, ScopeSink).
     latex_registered_subjects(sink, sink_a).
     latex_registered_subjects(sink, sink_b).
 )SCRIPT";
 
     typedef LatexBruteFunctionDecorator<compilation::BasicFunctionUnit> FnImpl;
     typedef LatexBruteScopeDecorator<compilation::CachedScopeDecorator<compilation::BasicCodeScopeUnit>> ScopeImpl;
 
     std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
     CodeScope* scopeSink = man->root->findFunction("fnSink")->getEntryScope();
     auto scopeSinkP = man->transcend->pack(scopeSink);
     ScopedSymbol argLatexSS{1, -1};
     Symbol argLatexS{argLatexSS, scopeSink};
     man->transcend->pack(argLatexS);
     boost::format format(script);
     man->transcend->addRawScript((format %scopeSinkP).str());
     man->transcend->registerQuery(new LatexQuery(), QueryId::LatexQuery);
     man->analyse();
 
     std::unique_ptr<CompilePass> compiler(new compilation::CompilePassCustomDecorators<FnImpl, ScopeImpl>(man.get()));
     compiler->run();
     man->llvm->print();
     man->llvm->initJit();
     int(*fnMain)() = (int(*)()) man->llvm->getFunctionPointer(compiler->getEntryFunction());
     int valueActual = fnMain();
     ASSERT_EQ(0, valueActual);
 }
 
 TEST(Latex, Doc_Examples1){
     std::string program = getDocumentationExampleById("documentation/Concepts/context.xml", "Examples_1");
     std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
 }
 
 TEST(Latex, Doc_Examples2){
   std::string program = getDocumentationExampleById("documentation/Concepts/context.xml", "Examples_2");
 
   std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
 }
 
 TEST(Latex, Doc_ContextPropagation1){
   std::string program =getDocumentationExampleById("documentation/Concepts/context.xml", "ContextPropagation1");
 
   std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
 }
 
 TEST(Latex, Doc_ContextPropagation2){
   std::string program = getDocumentationExampleById("documentation/Concepts/context.xml", "ContextPropagation2");
 
   std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
 }
 
-TEST(Latex, Doc_ContextPropagation3){
-  std::string program = getDocumentationExampleById("documentation/Concepts/context.xml", "ContextPropagation3");
-
-  std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
-}
-
 TEST(Latex, Doc_Latex1){
   std::string program = getDocumentationExampleById("documentation/Concepts/context.xml", "Latex1");
 
   std::unique_ptr<details::tier1::XreateManager> man(details::tier1::XreateManager::prepare(move(program)));
 }
\ No newline at end of file
diff --git a/documentation/build.xml b/documentation/build.xml
index 0b10cee..2f61382 100644
--- a/documentation/build.xml
+++ b/documentation/build.xml
@@ -1,154 +1,275 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <chapter version="5.1" xmlns="http://docbook.org/ns/docbook"
          xmlns:xlink="http://www.w3.org/1999/xlink"
          xmlns:xila="http://www.w3.org/2001/XInclude/local-attributes"
          xmlns:xi="http://www.w3.org/2001/XInclude"
          xmlns:trans="http://docbook.org/ns/transclusion"
          xmlns:svg="http://www.w3.org/2000/svg"
          xmlns:m="http://www.w3.org/1998/Math/MathML"
          xmlns:html="http://www.w3.org/1999/xhtml"
          xmlns:db="http://docbook.org/ns/docbook">
   <?xxe-sn 2ckdfwgr1fk 1?>
 
   <title><?xxe-sn 2ckdfwgr1fk 2?>Installation</title>
 
   <section>
     <?xxe-sn 2ckdfwgr1fk 6?>
 
     <title><?xxe-sn 2ckdfwgr1fk 7?>Build on Linux</title>
 
     <para><?xxe-sn 2ckdfwgr1fk 8?>Major dependencies:</para>
 
     <itemizedlist>
       <?xxe-sn 2ckdfwgr1fk 9?>
 
       <listitem>
         <?xxe-sn 2ckdfwgr1fk a?>
 
         <para><?xxe-sn 2ckdfwgr1fk b?>gcc 7</para>
       </listitem>
 
       <listitem>
         <?xxe-sn 2ckdfwgr1fk c?>
 
         <para><?xxe-sn 2ckdfwgr1fk d?>llvm 5, clang 5</para>
       </listitem>
 
       <listitem>
         <?xxe-sn 2ckdfwgr1fk e?>
 
         <para><?xxe-sn 2ckdfwgr1fk f?>boost 1.66</para>
       </listitem>
 
       <listitem>
         <?xxe-sn 2ckdfwgr1fk g?>
 
         <para><?xxe-sn 2ckdfwgr1fk h?>coco</para>
       </listitem>
 
       <listitem>
         <?xxe-sn 2ckdfwgr1fk i?>
 
         <para><?xxe-sn 2ckdfwgr1fk j?>clingo</para>
       </listitem>
     </itemizedlist>
 
     <para><?xxe-sn 2ckdfwgr1fk k?>Building tested on <emphasis
     role="bold"><?xxe-sn 2ckdfwgr1fk l?>OpenSuse Leap 15</emphasis>. Please
     change commands accordingly if using other distributions.</para>
 
     <para><?xxe-sn 2ckdfwgr1fk m?>Pull sources directly from
     repository:</para>
 
-    <literallayout><?xxe-sn 2ckdfwgr1fk n?>git clone --recursive https://pgess@bitbucket.org/pgess/xreate.git</literallayout>
+    <literallayout><?xxe-sn 2ckdfwgr1fk n?>git clone --recursive http://xreate.org/diffusion/XR/xreate.git</literallayout>
 
     <para><?xxe-sn 2ckdfwgr1fk o?>Enter into the source directory and run the
     following script to prepare building environment. Script will install the
     required system packages as well as Coco and Clingo from sources:</para>
 
     <remark><?xxe-sn 2ckdfwgr1fk p?>"Enter into source directory" - тут перед
     directory явно нужен артикль. Гугл говорит, что определенный -
     the</remark>
 
     <important>
       <?xxe-sn 2ckdfwgr1fk q?>
 
       <para><?xxe-sn 2ckdfwgr1fk r?>Carefully inspect scripts before
       run</para>
     </important>
 
     <para><?xxe-sn 2ckdfwgr1fk s?>On <emphasis role="bold"><?xxe-sn 2ckdfwgr1fk t?>OpenSuse
     Leap 15</emphasis>:</para>
 
     <literallayout><?xxe-sn 2ckdfwgr1fk u?>./installation/prepare-opensuse-leap15</literallayout>
 
     <para><?xxe-sn 2ckdfwgr1fk v?>That was one time operation to prepare
     environment. After that enter into <code><?xxe-sn 2ckdfwgr1fk w?>build</code>
     directory and start actual tests building:</para>
 
     <remark><?xxe-sn 2ckdfwgr1fk x?>"build directory": здесь ты все-таки
     вначале указываешь имя объекта (build), и лишь потом родовое название
     (directory)</remark>
 
     <literallayout><?xxe-sn 2ckdfwgr1fk y?>cd build
 make</literallayout>
 
     <para><?xxe-sn 2ckdfwgr1fk z?>After successful build you can run xreate
     tests:</para>
 
     <literallayout><?xxe-sn 2ckdfwgr1fk 10?>cd ..
 ./build/tests/xreate-tests</literallayout>
 
     <note>
       <?xxe-sn 2ckdfwgr1fk 11?>
 
       <para><?xxe-sn 2ckdfwgr1fk 12?>Please pay attention that the working
       directory should be the repository root</para>
     </note>
 
     <para><?xxe-sn 2ckdfwgr1fk 13?>For consequent rebuilds after updates etc
     invoke <code><?xxe-sn 2ckdfwgr1fk 14?>cmake</code> as follows:</para>
 
     <literallayout><?xxe-sn 2ckdfwgr1fk 15?>#working dir build
 cmake -DCMAKE_BUILD_TYPE=Debug \
       -DBUILD_XREATE_TESTS=1   \
       -DCOCO_EXECUTABLE=&lt;FILE&gt; \
       -DCLINGO_PATH=&lt;DIR&gt;      \
       -DCOCO_FRAMES_PATH=../vendors/coco/generator/  \
       -DCMAKE_CXX_COMPILER=g++ ../cpp
 make</literallayout>
 
-    <para><?xxe-sn 2ckdfwgr1fk 16?>Cmake's selected parameters:</para>
+    <para><?xxe-sn 2ckdfwgr1fk 16?><code><?xxe-sn 2coi7ojavb4 a?>cmake</code>'s
+    selected parameters:</para>
 
     <itemizedlist>
       <?xxe-sn 2ckdfwgr1fk 17?>
 
       <listitem>
         <?xxe-sn 2ckdfwgr1fk 18?>
 
         <para><?xxe-sn 2ckdfwgr1fk 19?>BUILD_XREATE_TESTS Determines whether
         to build tests</para>
       </listitem>
 
       <listitem>
         <?xxe-sn 2ckdfwgr1fk 1a?>
 
         <para><?xxe-sn 2ckdfwgr1fk 1b?>COCO_EXECUTABLE Full filename of Coco
         executable</para>
       </listitem>
 
       <listitem>
         <?xxe-sn 2ckdfwgr1fk 1c?>
 
         <para><?xxe-sn 2ckdfwgr1fk 1d?>CLINGO_PATH Installed Clingo
         directory</para>
 
         <remark><?xxe-sn 2ckdfwgr1fk 1e?>"Directory of Clingo installation":
         может, with Clingo installation? (это если речь идет о папке, где
         хранятся инсталляционные файлы) Если наоборот, куда будет
         устанавливаться - тогда Directory for installing Clingo. Оригинальный
         вариант ("of Clingo installation") немного сбивает с толку.</remark>
       </listitem>
     </itemizedlist>
   </section>
+
+  <section>
+    <?xxe-sn 2coi7ojavb4 1?>
+
+    <title condition="demo"><?xxe-sn 2coi7ojavb4 2?>Experimenting</title>
+
+    <para><?xxe-sn 2coi7ojavb4 3?>At this point the only executable produced
+    by <code><?xxe-sn 2coi7ojavb4 x?>make</code> is a collection of the unit
+    tests. There are many existing unit tests located in the <code><?xxe-sn 2coi7ojavb4 y?>cpp/tests</code>
+    to check correctness of various compilation aspects. Unit tests are
+    configured via the file <code><?xxe-sn 2coi7ojavb4 5?>config/default.json</code>
+    with the relevant settings located in the section <code><?xxe-sn 2coi7ojavb4 6?>tests</code>.
+    The section looks like this:</para>
+
+    <literallayout><?xxe-sn 2coi7ojavb4 b?>"tests": { 
+      "template": "default",
+      
+      "templates": {
+        "default": "*",
+
+        "documentation": "Modules.Doc_*:Modules_API.Doc_*",
+        "ast": "AST.*",
+        ...
+      }
+}</literallayout>
+
+    <para><?xxe-sn 2coi7ojavb4 c?>Key <code><?xxe-sn 2coi7ojavb4 d?>tests.template</code>
+    determines which group of unit tests should be executed, while section
+    <code><?xxe-sn 2coi7ojavb4 e?>test.templates</code> describes all
+    available groups. Note, that exact syntax of unit tests selection is
+    described in the Google Tests library documentation. By modifying this
+    configuration you can choose which tests you want to execute. </para>
+
+    <para><?xxe-sn 2coi7ojavb4 f?>In order to experiment with the compiler you
+    need to write your own unit-tests. There are several steps to complete to
+    add and run new unit tests:</para>
+
+    <itemizedlist>
+      <?xxe-sn 2coi7ojavb4 g?>
+
+      <listitem>
+        <?xxe-sn 2coi7ojavb4 h?>
+
+        <para><?xxe-sn 2coi7ojavb4 i?>Add new file to the <code><?xxe-sn 2coi7ojavb4 j?>cpp/tests</code>.</para>
+      </listitem>
+
+      <listitem>
+        <?xxe-sn 2coi7ojavb4 k?>
+
+        <para><?xxe-sn 2coi7ojavb4 l?>Register test by adding its filename to
+        the variable <code><?xxe-sn 2coi7ojavb4 10?>TEST_FILES</code> in the
+        <code><?xxe-sn 2coi7ojavb4 m?>test/CMakeLists.txt</code>.</para>
+      </listitem>
+
+      <listitem>
+        <?xxe-sn 2coi7ojavb4 n?>
+
+        <para><?xxe-sn 2coi7ojavb4 o?>Change <code><?xxe-sn 2coi7ojavb4 p?>config/default.json</code>
+        accordingly.</para>
+      </listitem>
+    </itemizedlist>
+
+    <para><?xxe-sn 2coi7ojavb4 q?>Below is a bare bones example of a unit-test
+    as a starting point to get an idea:</para>
+
+    <literallayout><?xxe-sn 2coi7ojavb4 r?>name="tests/unit-test-example: Example.Example1", lines=15
+#include "xreatemanager.h"    //main Xreate header
+#include "transcendlayer.h"
+#include &lt;gtest/gtest.h&gt;
+
+using namespace xreate;
+using namespace std;
+
+TEST(Example, Example1){
+  //(Optional) Your custom transcend rules if any
+  string rules = 
+  R"SCRIPT(
+    bind_func(sum, entry).
+  )SCRIPT";
+    
+  //Your custom program
+  string example = 
+  R"CODE(
+    //Custom code
+    
+    sum = function(a:: int, b:: int):: int
+    { 
+      a + b
+    }
+  )CODE";
+    
+  //Initialize compiler  
+  unique_ptr&lt;XreateManager&gt; man(XreateManager::prepare(move(example)));
+  
+  //Add transcend part:
+  man-&gt;transcend-&gt;addRawScript(move(rules));
+  
+  //Define signature of your entry function:
+  typedef int (*ENTRYFN)(int, int);
+    
+  //Compile the example and get a pointer to the entry function:
+  ENTRYFN yourEntryFn =  (ENTRYFN) man-&gt;run();
+  
+  //Now execute function and check the result
+  int resultActual = yourEntryFn(5, 7);
+  int resultExpected = 5 + 7;
+  
+  ASSERT_EQ(resultExpected, resultActual);
+}</literallayout>
+
+    <para><?xxe-sn 2coi7ojavb4 u?>It outlines common unit test structure:
+    defines a program and optional transcend rules(in this case to designate
+    <code><?xxe-sn 2coi7ojavb4 w?>sum</code> as an entry function). Then the
+    program is compiled, executed and the result is checked against expected
+    value. </para>
+
+    <para><?xxe-sn 2coi7ojavb4 11?>Have a look at other existing unit tests
+    and see <link xlink:href="/api"><?xxe-sn 2coi7ojavb4 z?>Internal
+    API</link> to know more. </para>
+  </section>
 </chapter>