diff --git a/common/Alias/View.php b/common/Alias/View.php
new file mode 100644
index 0000000..f28aeda
--- /dev/null
+++ b/common/Alias/View.php
@@ -0,0 +1,5 @@
+<?php
+namespace ProVM\Common\Alias;
+
+interface View {
+}
diff --git a/common/Controller/Home.php b/common/Controller/Home.php
new file mode 100644
index 0000000..1f9b700
--- /dev/null
+++ b/common/Controller/Home.php
@@ -0,0 +1,12 @@
+<?php
+namespace ProVM\Common\Controller;
+
+use Psr\Http\Message\ServerRequestInterface as Request;
+use Psr\Http\Message\ResponseInterface as Response;
+use ProVM\Common\Alias\View;
+
+class Home {
+  public function __invoke(Request $request, Response $response, View $view) {
+    return $view->render($response, 'home');
+  }
+}
diff --git a/common/Definition/View.php b/common/Definition/View.php
new file mode 100644
index 0000000..cfc21c6
--- /dev/null
+++ b/common/Definition/View.php
@@ -0,0 +1,8 @@
+<?php
+namespace ProVM\Common\Definition;
+
+use Slim\Views\Blade;
+use ProVM\Common\Alias\View as ViewInterface;
+
+class View extends Blade implements ViewInterface {
+}
diff --git a/common/Helper/Merger.php b/common/Helper/Merger.php
new file mode 100644
index 0000000..3e6ec60
--- /dev/null
+++ b/common/Helper/Merger.php
@@ -0,0 +1,21 @@
+<?php
+namespace ProVM\Common\Helper;
+
+class Merger {
+  protected $separator;
+  public function __construct(string $separator) {
+    $this->separator = $separator;
+  }
+  protected $array;
+  public function start(): Merger {
+    $this->array = [];
+    return $this;
+  }
+  public function add($element): Merger {
+    $this->array []= $element;
+    return $this;
+  }
+  public function merge() {
+    return implode($this->separator, $this->array);
+  }
+}
diff --git a/common/Helper/Tree.php b/common/Helper/Tree.php
new file mode 100644
index 0000000..38a9f00
--- /dev/null
+++ b/common/Helper/Tree.php
@@ -0,0 +1,58 @@
+<?php
+namespace ProVM\Common\Helper;
+
+class Tree {
+  protected $merger;
+  public function __construct($separator) {
+    $this->merger = new Merger($separator);
+  }
+  protected $tree;
+  public function add($value, $parent = null, $alias = null): Tree {
+    if ($parent === null) {
+      if ($alias === null) {
+        $this->tree []= $value;
+        return $this;
+      }
+      $this->tree[$alias] = $value;
+      return $this;
+    }
+    if (!isset($this->tree[$parent])) {
+      return $this;
+    }
+    if ($alias === null) {
+      $this->tree []= $this->merger->start()
+        ->add($this->tree[$parent])
+        ->add($value)
+        ->merge();
+      return $this;
+    }
+    $this->tree[$alias] = $this->merger->start()
+      ->add($this->tree[$parent])
+      ->add($value)
+      ->merge();
+    return $this;
+  }
+  public function check_keys($tree) {
+    $bool = true;
+    foreach ($tree as $def) {
+      if (!isset($def[2])) {
+        continue;
+      }
+      $key = $def[2];
+      $bool &= array_key_exists($key, $this->tree);
+    }
+    return $bool;
+  }
+  public function addTree($tree) {
+    while (!$this->check_keys($tree)) {
+      foreach ($tree as $def) {
+        $this->add($def[0], $def[1] ?? null, $def[2] ?? null);
+      }
+    }
+  }
+  public function build($tree) {
+    $this->tree = [];
+    $this->addTree($tree);
+    return (object) $this->tree;
+  }
+}