diff --git a/CHANGELOG.md b/CHANGELOG.md
index 286511327..4fba361d5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -26,6 +26,7 @@
 - Move MST to core
 - Separated benchmarks and examples
 - Rewritten EJML module without ejml-simple
+- Stability of kmath-ast and kmath-kotilngrad promoted to EXPERIMENTAL.
 
 ### Deprecated
 
@@ -35,7 +36,7 @@
 - `contentEquals` from Buffer. It moved to the companion.
 - MSTExpression
 - Expression algebra builders
-- Comples and Quaternion no longer are elements.
+- Complex and Quaternion no longer are elements.
 
 ### Fixed
 - Ring inherits RingOperations, not GroupOperations
diff --git a/README.md b/README.md
index c8da21b64..3b4387c1b 100644
--- a/README.md
+++ b/README.md
@@ -207,9 +207,14 @@ One can still use generic algebras though.
 <hr/>
 
 * ### [kmath-kotlingrad](kmath-kotlingrad)
-> 
+> Functions, integration and interpolation
 >
-> **Maturity**: PROTOTYPE
+> **Maturity**: EXPERIMENTAL
+>
+> **Features:**
+> - [differentiable-mst-expression](kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt) : MST based DifferentiableExpression.
+> - [differentiable-mst-expression](kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt) : Conversions between Kotlin&nabla;'s SFun and MST
+
 <hr/>
 
 * ### [kmath-memory](kmath-memory)
diff --git a/kmath-kotlingrad/README.md b/kmath-kotlingrad/README.md
new file mode 100644
index 000000000..686df3271
--- /dev/null
+++ b/kmath-kotlingrad/README.md
@@ -0,0 +1,34 @@
+# Module kmath-kotlingrad
+
+[Kotlin∇](https://github.com/breandan/kotlingrad) integration module.
+
+ - [differentiable-mst-expression](src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt) : MST based DifferentiableExpression.
+ - [differentiable-mst-expression](src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt) : Conversions between Kotlin∇'s SFun and MST
+
+
+## Artifact:
+
+The Maven coordinates of this project are `space.kscience:kmath-kotlingrad:0.3.0-dev-8`.
+
+**Gradle:**
+```gradle
+repositories {
+    maven { url 'https://repo.kotlin.link' }
+    mavenCentral()
+}
+
+dependencies {
+    implementation 'space.kscience:kmath-kotlingrad:0.3.0-dev-8'
+}
+```
+**Gradle Kotlin DSL:**
+```kotlin
+repositories {
+    maven("https://repo.kotlin.link")
+    mavenCentral()
+}
+
+dependencies {
+    implementation("space.kscience:kmath-kotlingrad:0.3.0-dev-8")
+}
+```
diff --git a/kmath-kotlingrad/build.gradle.kts b/kmath-kotlingrad/build.gradle.kts
index ed5b5bcb4..0e8e49971 100644
--- a/kmath-kotlingrad/build.gradle.kts
+++ b/kmath-kotlingrad/build.gradle.kts
@@ -4,11 +4,27 @@ plugins {
 }
 
 dependencies {
-    api("com.github.breandan:kaliningraph:0.1.4")
+    api("com.github.breandan:kaliningraph:0.1.6")
     api("com.github.breandan:kotlingrad:0.4.5")
     api(project(":kmath-ast"))
 }
 
 readme {
-    maturity = ru.mipt.npm.gradle.Maturity.PROTOTYPE
+    description = "Functions, integration and interpolation"
+    maturity = ru.mipt.npm.gradle.Maturity.EXPERIMENTAL
+    propertyByTemplate("artifact", rootProject.file("docs/templates/ARTIFACT-TEMPLATE.md"))
+
+    feature(
+        "differentiable-mst-expression",
+        "src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt",
+    ) {
+        "MST based DifferentiableExpression."
+    }
+
+    feature(
+        "differentiable-mst-expression",
+        "src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt",
+    ) {
+        "Conversions between Kotlin∇'s SFun and MST"
+    }
 }
diff --git a/kmath-kotlingrad/docs/README-TEMPLATE.md b/kmath-kotlingrad/docs/README-TEMPLATE.md
new file mode 100644
index 000000000..ac38c849b
--- /dev/null
+++ b/kmath-kotlingrad/docs/README-TEMPLATE.md
@@ -0,0 +1,7 @@
+# Module kmath-kotlingrad
+
+[Kotlin∇](https://www.htmlsymbols.xyz/unicode/U+2207) integration module.
+
+${features}
+
+${artifact}
diff --git a/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt b/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt
index 222145d2d..8c6745c79 100644
--- a/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt
+++ b/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/DifferentiableMstExpression.kt
@@ -6,6 +6,7 @@
 package space.kscience.kmath.kotlingrad
 
 import edu.umontreal.kotlingrad.api.SFun
+import edu.umontreal.kotlingrad.api.SVar
 import space.kscience.kmath.expressions.DifferentiableExpression
 import space.kscience.kmath.expressions.MST
 import space.kscience.kmath.expressions.MstAlgebra
@@ -14,20 +15,20 @@ import space.kscience.kmath.misc.Symbol
 import space.kscience.kmath.operations.NumericAlgebra
 
 /**
- * Represents wrapper of [MstExpression] implementing [DifferentiableExpression].
+ * Represents [MST] based [DifferentiableExpression].
  *
- * The principle of this API is converting the [mst] to an [SFun], differentiating it with Kotlin∇, then converting
- * [SFun] back to [MST].
+ * The principle of this API is converting the [mst] to an [SFun], differentiating it with
+ * [Kotlin∇](https://github.com/breandan/kotlingrad), then converting [SFun] back to [MST].
  *
- * @param T the type of number.
- * @param A the [NumericAlgebra] of [T].
- * @property expr the underlying [MstExpression].
+ * @param T The type of number.
+ * @param A The [NumericAlgebra] of [T].
+ * @property algebra The [A] instance.
+ * @property mst The [MST] node.
  */
 public class DifferentiableMstExpression<T : Number, A : NumericAlgebra<T>>(
     public val algebra: A,
     public val mst: MST,
 ) : DifferentiableExpression<T, DifferentiableMstExpression<T, A>> {
-
     public override fun invoke(arguments: Map<Symbol, T>): T = mst.interpret(algebra, arguments)
 
     public override fun derivativeOrNull(symbols: List<Symbol>): DifferentiableMstExpression<T, A> =
@@ -35,7 +36,7 @@ public class DifferentiableMstExpression<T : Number, A : NumericAlgebra<T>>(
             algebra,
             symbols.map(Symbol::identity)
                 .map(MstAlgebra::bindSymbol)
-                .map { it.toSVar<KMathNumber<T, A>>() }
+                .map<MST.Symbolic, SVar<KMathNumber<T, A>>>(MST.Symbolic::toSVar)
                 .fold(mst.toSFun(), SFun<KMathNumber<T, A>>::d)
                 .toMst(),
         )
diff --git a/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/KMathNumber.kt b/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/KMathNumber.kt
index 0c3768dcc..9c9d07b81 100644
--- a/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/KMathNumber.kt
+++ b/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/KMathNumber.kt
@@ -5,19 +5,26 @@
 
 package space.kscience.kmath.kotlingrad
 
-import edu.umontreal.kotlingrad.api.RealNumber
 import edu.umontreal.kotlingrad.api.SConst
 import space.kscience.kmath.operations.NumericAlgebra
 
 /**
- * Implements [RealNumber] by delegating its functionality to [NumericAlgebra].
+ * Implements [SConst] by delegating its functionality to [NumericAlgebra].
  *
- * @param T the type of number.
- * @param A the [NumericAlgebra] of [T].
- * @property algebra the algebra.
- * @param value the value of this number.
+ * @param T The type of number.
+ * @param A The [NumericAlgebra] over [T].
+ * @property algebra The algebra.
+ * @property value The value of this number.
  */
-public class KMathNumber<T, A>(public val algebra: A, value: T) :
-    RealNumber<KMathNumber<T, A>, T>(value) where T : Number, A : NumericAlgebra<T> {
-    public override fun wrap(number: Number): SConst<KMathNumber<T, A>> = SConst(algebra.number(number))
+public class KMathNumber<T, A>(public val algebra: A, public override val value: T) :
+    SConst<KMathNumber<T, A>>(value) where T : Number, A : NumericAlgebra<T> {
+    /**
+     * Returns a string representation of the [value].
+     */
+    public override fun toString(): String = value.toString()
+
+    /**
+     * Wraps [Number] to [KMathNumber].
+     */
+    public override fun wrap(number: Number): KMathNumber<T, A> = KMathNumber(algebra, algebra.number(number))
 }
diff --git a/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/ScalarsAdapters.kt b/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/ScalarsAdapters.kt
index f65d2948d..bee2c9e3e 100644
--- a/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/ScalarsAdapters.kt
+++ b/kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/ScalarsAdapters.kt
@@ -15,16 +15,16 @@ import space.kscience.kmath.operations.*
 /**
  * Maps [SVar] to [MST.Symbolic] directly.
  *
- * @receiver the variable.
- * @return a node.
+ * @receiver The variable.
+ * @returnAa node.
  */
 public fun <X : SFun<X>> SVar<X>.toMst(): MST.Symbolic = MstAlgebra.bindSymbol(name)
 
 /**
  * Maps [SVar] to [MST.Numeric] directly.
  *
- * @receiver the constant.
- * @return a node.
+ * @receiver The constant.
+ * @return A node.
  */
 public fun <X : SFun<X>> SConst<X>.toMst(): MST.Numeric = MstAlgebra.number(doubleValue)
 
@@ -49,8 +49,8 @@ public fun <X : SFun<X>> SConst<X>.toMst(): MST.Numeric = MstAlgebra.number(doub
  * - [VSumAll] is requested to be evaluated;
  * - [Derivative] is requested to be evaluated.
  *
- * @receiver the scalar function.
- * @return a node.
+ * @receiver The scalar function.
+ * @return A node.
  */
 public fun <X : SFun<X>> SFun<X>.toMst(): MST = MstExtendedField {
     when (this@toMst) {
@@ -74,17 +74,16 @@ public fun <X : SFun<X>> SFun<X>.toMst(): MST = MstExtendedField {
 /**
  * Maps [MST.Numeric] to [SConst] directly.
  *
- * @receiver the node.
- * @return a new constant.
+ * @receiver The node.
+ * @return A new constant.
  */
 public fun <X : SFun<X>> MST.Numeric.toSConst(): SConst<X> = SConst(value)
 
 /**
  * Maps [MST.Symbolic] to [SVar] directly.
  *
- * @receiver the node.
- * @param proto the prototype instance.
- * @return a new variable.
+ * @receiver The node.
+ * @return A new variable.
  */
 internal fun <X : SFun<X>> MST.Symbolic.toSVar(): SVar<X> = SVar(value)
 
@@ -98,9 +97,8 @@ internal fun <X : SFun<X>> MST.Symbolic.toSVar(): SVar<X> = SVar(value)
  * - [MST.Unary] -> [Negative], [Sine], [Cosine], [Tangent], [Power], [Log];
  * - [MST.Binary] -> [Sum], [Prod], [Power].
  *
- * @receiver the node.
- * @param proto the prototype instance.
- * @return a scalar function.
+ * @receiver The node.
+ * @return A scalar function.
  */
 public fun <X : SFun<X>> MST.toSFun(): SFun<X> = when (this) {
     is MST.Numeric -> toSConst()
diff --git a/kmath-kotlingrad/src/test/kotlin/space/kscience/kmath/kotlingrad/AdaptingTests.kt b/kmath-kotlingrad/src/test/kotlin/space/kscience/kmath/kotlingrad/AdaptingTests.kt
index 3ed73451d..85c964c58 100644
--- a/kmath-kotlingrad/src/test/kotlin/space/kscience/kmath/kotlingrad/AdaptingTests.kt
+++ b/kmath-kotlingrad/src/test/kotlin/space/kscience/kmath/kotlingrad/AdaptingTests.kt
@@ -10,7 +10,7 @@ import space.kscience.kmath.asm.compileToExpression
 import space.kscience.kmath.ast.parseMath
 import space.kscience.kmath.expressions.MstAlgebra
 import space.kscience.kmath.expressions.invoke
-import space.kscience.kmath.misc.symbol
+import space.kscience.kmath.misc.Symbol.Companion.x
 import space.kscience.kmath.operations.DoubleField
 import kotlin.test.Test
 import kotlin.test.assertEquals
@@ -65,8 +65,4 @@ internal class AdaptingTests {
 
         assertEquals(actualDerivative(x to 0.1), expectedDerivative(x to 0.1))
     }
-
-    private companion object {
-        private val x by symbol
-    }
 }