diff --git a/.gitignore b/.gitignore
index 039dbd9..0b4b183 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,3 +19,4 @@ cmake-build-debug
 
 .idea
 .cache
+.ccls-cache
diff --git a/include/type_check_utils.hpp b/include/type_check_utils.hpp
index 7e8e079..f069fae 100644
--- a/include/type_check_utils.hpp
+++ b/include/type_check_utils.hpp
@@ -17,8 +17,8 @@ class State {
 
 public:
   struct VariableInfo {
-      nodes::TypeProxy type;
-      nodes::NameDefinition::Modifier modifier;
+    nodes::TypeProxy type;
+    nodes::NameDefinition::Modifier modifier;
   };
 
 public:
@@ -29,11 +29,12 @@ public:
           "Insert variable into contexts_ with zero elements in State");
     }
 
-    return contexts_.back().variables.insert({name, VariableInfo{type, modifier}}).second;
+    return contexts_.back()
+        .variables.insert({name, VariableInfo{type, modifier}})
+        .second;
   }
 
-  std::optional<VariableInfo>
-  find_variable(const std::string &name) {
+  std::optional<VariableInfo> find_variable(const std::string &name) {
     for (ssize_t i = contexts_.size(); i >= 0; --i) {
       auto iter = contexts_[i].variables.find(name);
       if (iter != contexts_[i].variables.end()) {
@@ -134,8 +135,7 @@ public:
   public:
     nodes::MaybeTypeProxy brought_type;
     nodes::MaybeTypeProxy returned_type;
-    std::unordered_map<std::string, VariableInfo>
-        variables;
+    std::unordered_map<std::string, VariableInfo> variables;
 
   private:
     const nodes::Node &node;
@@ -266,6 +266,15 @@ find_name_definition_handle_errors(const std::string &name,
                                    const nodes::Node &node,
                                    SourcesManager &sources_manager);
 
+std::optional<nodes::TypeProxy>
+unfold_user_defined_type_handle_errors(nodes::TypeProxy type,
+                                       const nodes::Node &node,
+                                       SourcesManager &sources_manager);
+
+std::optional<nodes::TypeProxy> get_field_type_by_name_handle_errors(
+    nodes::TypeProxy type, const std::string &field, const nodes::Node &node,
+    SourcesManager &sources_manager);
+
 void type_check_error(const std::string &message, const nodes::Node &node,
                       SourcesManager &sources_manager);
 
diff --git a/src/type_check_utils.cpp b/src/type_check_utils.cpp
index 95d3db3..5e552e4 100644
--- a/src/type_check_utils.cpp
+++ b/src/type_check_utils.cpp
@@ -1,4 +1,5 @@
 #include "type_check_utils.hpp"
+#include "builtin_types.hpp"
 #include <algorithm>
 
 namespace type_check {
@@ -32,19 +33,22 @@ bool check_no_pass_type_in_arguments(const Arguments &arguments,
   return true;
 }
 
-nodes::TypeCheckResult
-type_same_to_expected(nodes::TypeProxy type,
-                      const Arguments& arguments,
-                      const nodes::Node &node, SourcesManager &sources_manager,
-                      const std::string &message) {
-  const auto& expected = arguments.get_expected();
+nodes::TypeCheckResult type_same_to_expected(nodes::TypeProxy type,
+                                             const Arguments &arguments,
+                                             const nodes::Node &node,
+                                             SourcesManager &sources_manager,
+                                             const std::string &message) {
+  const auto &expected = arguments.get_expected();
 
   if (expected.empty()) {
     return nodes::TypeCheckResult{type};
   }
 
   // TODO: use 'can cast to' (for modifiers), instead '=='
-  if (std::all_of(expected.begin(), expected.end(), [type](nodes::TypeProxy expected_type) { return type != expected_type; })) {
+  if (std::all_of(expected.begin(), expected.end(),
+                  [type](nodes::TypeProxy expected_type) {
+                    return type != expected_type;
+                  })) {
     type_check_error(message, node, sources_manager);
   }
 
@@ -95,6 +99,78 @@ find_name_definition_handle_errors(const std::string &name,
       "Node in name tree is not name definition");
 }
 
+std::optional<nodes::TypeProxy>
+unfold_user_defined_type_handle_errors(nodes::TypeProxy type,
+                                       const nodes::Node &node,
+                                       SourcesManager &sources_manager) {
+  const auto maybe_type_definition = find_type_definition_handle_errors(
+      *type.get()->get_name()->get(), node, sources_manager);
+
+  if (!maybe_type_definition.has_value()) {
+    return std::nullopt;
+  }
+
+  if (maybe_type_definition.value()->get_type().has_value()) {
+    sources_manager.get_error_log()->add_error(
+        error_handling::ErrorLog::ErrorMessage(
+            node,
+            "Only type declaration found for type " +
+                *type.get()->get_name()->get() + " (type is not defined)",
+            error_handling::ErrorType::TYPE_CHECK));
+    return std::nullopt;
+  }
+
+  // TODO: perform type arguments substitution
+  error_handling::ensure(type.get()->parameters_size() == 0,
+                         "Unfold of generic type is not supported (yet)");
+  //
+  return maybe_type_definition.value()->get_type().value();
+}
+
+std::optional<nodes::TypeProxy> get_field_type_by_name_handle_errors(
+    nodes::TypeProxy type, const std::string &field, const nodes::Node &node,
+    SourcesManager &sources_manager) {
+  switch (type.get()->to_builtin()) {
+  case builtin::types::Type::TUPLE: { // access field
+
+    const auto maybe_field = type.get()->get_parameter_proxy_by_name(field);
+
+    if (!maybe_field.has_value()) {
+
+      // TODO: pass unfolded type name to log it ??
+      sources_manager.get_error_log()->add_error(
+          error_handling::ErrorLog::ErrorMessage(
+              node, "Type has no defined field " + field,
+              error_handling::ErrorType::TYPE_CHECK));
+    }
+    return maybe_field.value();
+  }
+  case builtin::types::Type::NONE: { // user defined type, trying to unfold, and
+                                     // then repeat access
+
+    // remove recursion ??
+    const auto maybe_internal_type =
+        unfold_user_defined_type_handle_errors(type, node, sources_manager);
+    if (!maybe_internal_type.has_value()) {
+      return std::nullopt;
+    }
+
+    return get_field_type_by_name_handle_errors(maybe_internal_type.value(),
+                                                field, node, sources_manager);
+  }
+  default: // variant, function, optional, result, error (TODO: add message
+           // field?), array (TODO: add length field ?), basic types
+
+    sources_manager.get_error_log()->add_error(
+        error_handling::ErrorLog::ErrorMessage(
+            node,
+            "Type " + builtin::types::to_string(type.get()->to_builtin()) +
+                " has no accessible fields by definition",
+            error_handling::ErrorType::TYPE_CHECK));
+    return std::nullopt;
+  }
+}
+
 void type_check_error(const std::string &message, const nodes::Node &node,
                       SourcesManager &sources_manager) {
   sources_manager.get_error_log()->add_error(