diff --git a/docs/design.md b/docs/design.md
index 79014d73..17e52a35 100644
--- a/docs/design.md
+++ b/docs/design.md
@@ -14,6 +14,6 @@ The actual layering scheme is more complicated. All objects support styling. The
 
 ### Intermediate representation
 
-An important thing about VisionForge is that it does not strictly bound to a single format representation. 
+An important thing about VisionForge is that it does not strictly bound to a single format representation.
 
 ### Kotlin DSL for creating vision-graphs
\ No newline at end of file
diff --git a/docs/hierarchy.md b/docs/hierarchy.md
new file mode 100644
index 00000000..eee02697
--- /dev/null
+++ b/docs/hierarchy.md
@@ -0,0 +1,32 @@
+# Hierarchy
+
+![](../docs/images/hierarchy.png)
+
+### Vision
+
+* function `getProperty(name: Name, inherit: Boolean, includeStyles: Boolean, includeDefaults: Boolean)`. 
+
+It gets properties of element with `name` identification.
+`inherit` — toggles parent node property lookup. Null means inference from descriptor. Default is false.
+`includeStyles` — toggles inclusion of. Null means inference from descriptor. Default is true. 
+`includeDefaults` — default is false.
+
+* function `setProperty(name: Name, item: MetaItem?, notify: Boolean = true)`
+
+Sets the `item` property to the element with the `name` identification. `notify` is a value which toggles the necessity of the change notification. Default is true.
+
+### About properties
+**Properties have to be set in particular order:**
+
+* styles
+* prototypes
+* parent
+* parent's styles
+* defaults
+
+
+## Inheritance
+
+Inheritance is a very useful ability of `children` elements to get the same property in default as his parent does have (to 'inherit' it). 
+
+
diff --git a/docs/images/hierarchy.png b/docs/images/hierarchy.png
new file mode 100644
index 00000000..e202c6af
Binary files /dev/null and b/docs/images/hierarchy.png differ
diff --git a/docs/tutorial.md b/docs/tutorial.md
index 886fe641..8989bd49 100644
--- a/docs/tutorial.md
+++ b/docs/tutorial.md
@@ -42,9 +42,7 @@ fun main(){
 *Basic properties:*
 1. `opacity` — It is set in `float`. It takes on values from 0 to 1, which represent percents of solid opacity. It's initial value is 1.
 2. `color` — It can be specified as `Int`, `String`, or as three `Ubytes`, which represent color in `rgb`. Elementally, the solid will have `green` color.
-
 3. `rotation` — it's the point, which sets rotations along axes. Initially, the value is `Point3D(0, 0, 0)`. Changing `x` coordinate of the point, you make pivot around `x axis`. The same for other coordinates: changing `y` — pivot around `y axis`, changing `z` — pivot around `z axis`.
-
 4. position, which is given by values `x`, `y`, `z`. Initial values are `x = 0`, `y = 0`, `z = 0`. The coordinate system is Cartesian. It's elemental position is this — vertical `y` axis and horizontal `Oxz` plane.
 
 Let's see how properties are set in solids.
diff --git a/docs/uml/Vision.puml b/docs/uml/Vision.puml
index 2028b097..d7fd7103 100644
--- a/docs/uml/Vision.puml
+++ b/docs/uml/Vision.puml
@@ -5,6 +5,7 @@ interface Vision{
     val parent: Vision?
     fun getProperty(name): MetaItem?
     fun setProperty(name, value)
+
 }
 
 class VisionBase{
diff --git a/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionBase.kt b/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionBase.kt
index 78b75124..08927448 100644
--- a/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionBase.kt
+++ b/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/VisionBase.kt
@@ -17,11 +17,6 @@ import space.kscience.dataforge.values.ValueType
 import space.kscience.visionforge.Vision.Companion.STYLE_KEY
 import kotlin.jvm.Synchronized
 
-internal data class PropertyListener(
-    val owner: Any? = null,
-    val action: (name: Name) -> Unit,
-)
-
 /**
  * A full base implementation for a [Vision]
  * @param properties Object own properties excluding styles and inheritance
@@ -43,7 +38,7 @@ public open class VisionBase(
     }
 
     /**
-     * A fast accessor method to get own property (no inheritance or styles
+     * A fast accessor method to get own property (no inheritance or styles)
      */
     override fun getOwnProperty(name: Name): MetaItem? = if (name == Name.EMPTY) {
         properties?.asMetaItem()