diff --git a/kmath-ast/build.gradle.kts b/kmath-ast/build.gradle.kts
index b4a0b28ac..508374d82 100644
--- a/kmath-ast/build.gradle.kts
+++ b/kmath-ast/build.gradle.kts
@@ -18,6 +18,10 @@ kotlin.js {
 }
 
 kotlin.sourceSets {
+    filter { it.name.contains("test", true) }
+        .map(org.jetbrains.kotlin.gradle.plugin.KotlinSourceSet::languageSettings)
+        .forEach { it.useExperimentalAnnotation("space.kscience.kmath.misc.UnstableKMathAPI") }
+
     commonMain {
         dependencies {
             api("com.github.h0tk3y.betterParse:better-parse:0.4.2")
@@ -54,7 +58,7 @@ tasks.dokkaHtml {
 }
 
 readme {
-    maturity = ru.mipt.npm.gradle.Maturity.PROTOTYPE
+    maturity = ru.mipt.npm.gradle.Maturity.EXPERIMENTAL
     propertyByTemplate("artifact", rootProject.file("docs/templates/ARTIFACT-TEMPLATE.md"))
 
     feature(
diff --git a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/parser.kt b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/parser.kt
index d2e92c37f..246625d29 100644
--- a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/parser.kt
+++ b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/parser.kt
@@ -29,7 +29,6 @@ import space.kscience.kmath.operations.RingOperations
  * @author Iaroslav Postovalov
  */
 public object ArithmeticsEvaluator : Grammar<MST>() {
-    // TODO replace with "...".toRegex() when better-parse 0.4.1 is released
     private val num: Token by regexToken("[\\d.]+(?:[eE][-+]?\\d+)?".toRegex())
     private val id: Token by regexToken("[a-z_A-Z][\\da-z_A-Z]*".toRegex())
     private val lpar: Token by literalToken("(")
diff --git a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/LatexSyntaxRenderer.kt b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/LatexSyntaxRenderer.kt
index 1c82bd6e7..5909f1f9d 100644
--- a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/LatexSyntaxRenderer.kt
+++ b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/LatexSyntaxRenderer.kt
@@ -5,6 +5,8 @@
 
 package space.kscience.kmath.ast.rendering
 
+import space.kscience.kmath.misc.UnstableKMathAPI
+
 /**
  * [SyntaxRenderer] implementation for LaTeX.
  *
@@ -23,6 +25,7 @@ package space.kscience.kmath.ast.rendering
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public object LatexSyntaxRenderer : SyntaxRenderer {
     public override fun render(node: MathSyntax, output: Appendable): Unit = output.run {
         fun render(syntax: MathSyntax) = render(syntax, output)
diff --git a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathMLSyntaxRenderer.kt b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathMLSyntaxRenderer.kt
index decd4ba46..517ec0dc9 100644
--- a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathMLSyntaxRenderer.kt
+++ b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathMLSyntaxRenderer.kt
@@ -5,6 +5,8 @@
 
 package space.kscience.kmath.ast.rendering
 
+import space.kscience.kmath.misc.UnstableKMathAPI
+
 /**
  * [SyntaxRenderer] implementation for MathML.
  *
@@ -12,9 +14,10 @@ package space.kscience.kmath.ast.rendering
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public object MathMLSyntaxRenderer : SyntaxRenderer {
     public override fun render(node: MathSyntax, output: Appendable) {
-        output.append("<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow>")
+        output.append("<math xmlns=\"https://www.w3.org/1998/Math/MathML\"><mrow>")
         render0(node, output)
         output.append("</mrow></math>")
     }
diff --git a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathRenderer.kt b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathRenderer.kt
index 9df2c54dd..6b22ac519 100644
--- a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathRenderer.kt
+++ b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathRenderer.kt
@@ -6,12 +6,14 @@
 package space.kscience.kmath.ast.rendering
 
 import space.kscience.kmath.expressions.MST
+import space.kscience.kmath.misc.UnstableKMathAPI
 
 /**
  * Renders [MST] to [MathSyntax].
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun interface MathRenderer {
     /**
      * Renders [MST] to [MathSyntax].
@@ -25,6 +27,7 @@ public fun interface MathRenderer {
  * @property features The applied features.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public open class FeaturedMathRenderer(public val features: List<RenderFeature>) : MathRenderer {
     public override fun render(mst: MST): MathSyntax {
         for (feature in features) feature.render(this, mst)?.let { return it }
@@ -48,6 +51,7 @@ public open class FeaturedMathRenderer(public val features: List<RenderFeature>)
  * @property stages The applied stages.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public open class FeaturedMathRendererWithPostProcess(
     features: List<RenderFeature>,
     public val stages: List<PostProcessStage>,
diff --git a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathSyntax.kt b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathSyntax.kt
index 6a46bf535..3c023e342 100644
--- a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathSyntax.kt
+++ b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/MathSyntax.kt
@@ -5,11 +5,14 @@
 
 package space.kscience.kmath.ast.rendering
 
+import space.kscience.kmath.misc.UnstableKMathAPI
+
 /**
  * Mathematical typography syntax node.
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public sealed class MathSyntax {
     /**
      * The parent node of this syntax node.
@@ -22,6 +25,7 @@ public sealed class MathSyntax {
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public sealed class TerminalSyntax : MathSyntax()
 
 /**
@@ -29,6 +33,7 @@ public sealed class TerminalSyntax : MathSyntax()
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public sealed class OperationSyntax : MathSyntax() {
     /**
      * The operation token.
@@ -41,6 +46,7 @@ public sealed class OperationSyntax : MathSyntax() {
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public sealed class UnarySyntax : OperationSyntax() {
     /**
      * The operand of this node.
@@ -53,6 +59,7 @@ public sealed class UnarySyntax : OperationSyntax() {
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public sealed class BinarySyntax : OperationSyntax() {
     /**
      * The left-hand side operand.
@@ -71,6 +78,7 @@ public sealed class BinarySyntax : OperationSyntax() {
  * @property string The digits of number.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class NumberSyntax(public var string: String) : TerminalSyntax()
 
 /**
@@ -79,6 +87,7 @@ public data class NumberSyntax(public var string: String) : TerminalSyntax()
  * @property string The symbol.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class SymbolSyntax(public var string: String) : TerminalSyntax()
 
 /**
@@ -89,6 +98,7 @@ public data class SymbolSyntax(public var string: String) : TerminalSyntax()
  * @see UnaryOperatorSyntax
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class OperatorNameSyntax(public var name: String) : TerminalSyntax()
 
 /**
@@ -97,6 +107,7 @@ public data class OperatorNameSyntax(public var name: String) : TerminalSyntax()
  * @property kind The kind of symbol.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class SpecialSymbolSyntax(public var kind: Kind) : TerminalSyntax() {
     /**
      * The kind of symbol.
@@ -121,6 +132,7 @@ public data class SpecialSymbolSyntax(public var kind: Kind) : TerminalSyntax()
  * @property parentheses Whether the operand should be wrapped with parentheses.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class OperandSyntax(
     public val operand: MathSyntax,
     public var parentheses: Boolean,
@@ -136,6 +148,7 @@ public data class OperandSyntax(
  * @property prefix The prefix.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class UnaryOperatorSyntax(
     public override val operation: String,
     public var prefix: MathSyntax,
@@ -151,6 +164,7 @@ public data class UnaryOperatorSyntax(
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class UnaryPlusSyntax(
     public override val operation: String,
     public override val operand: OperandSyntax,
@@ -165,6 +179,7 @@ public data class UnaryPlusSyntax(
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class UnaryMinusSyntax(
     public override val operation: String,
     public override val operand: OperandSyntax,
@@ -180,6 +195,7 @@ public data class UnaryMinusSyntax(
  * @property operand The radicand.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class RadicalSyntax(
     public override val operation: String,
     public override val operand: MathSyntax,
@@ -197,6 +213,7 @@ public data class RadicalSyntax(
  * (*e<sup>x</sup>*).
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class ExponentSyntax(
     public override val operation: String,
     public override val operand: OperandSyntax,
@@ -214,6 +231,7 @@ public data class ExponentSyntax(
  * @property right The superscript.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class SuperscriptSyntax(
     public override val operation: String,
     public override val left: MathSyntax,
@@ -232,6 +250,7 @@ public data class SuperscriptSyntax(
  * @property right The subscript.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class SubscriptSyntax(
     public override val operation: String,
     public override val left: MathSyntax,
@@ -249,6 +268,7 @@ public data class SubscriptSyntax(
  * @property prefix The prefix.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class BinaryOperatorSyntax(
     public override val operation: String,
     public var prefix: MathSyntax,
@@ -268,6 +288,7 @@ public data class BinaryOperatorSyntax(
  * @param right The addend.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class BinaryPlusSyntax(
     public override val operation: String,
     public override val left: OperandSyntax,
@@ -286,6 +307,7 @@ public data class BinaryPlusSyntax(
  * @param right The subtrahend.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class BinaryMinusSyntax(
     public override val operation: String,
     public override val left: OperandSyntax,
@@ -304,6 +326,7 @@ public data class BinaryMinusSyntax(
  * @property right The denominator.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class FractionSyntax(
     public override val operation: String,
     public override val left: MathSyntax,
@@ -322,6 +345,7 @@ public data class FractionSyntax(
  * @property right The radicand.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class RadicalWithIndexSyntax(
     public override val operation: String,
     public override val left: MathSyntax,
@@ -341,6 +365,7 @@ public data class RadicalWithIndexSyntax(
  * @property times whether the times (&times;) symbol should be used.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public data class MultiplicationSyntax(
     public override val operation: String,
     public override val left: OperandSyntax,
diff --git a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/SyntaxRenderer.kt b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/SyntaxRenderer.kt
index 7fa91e158..fb2b3b66f 100644
--- a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/SyntaxRenderer.kt
+++ b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/SyntaxRenderer.kt
@@ -5,12 +5,15 @@
 
 package space.kscience.kmath.ast.rendering
 
+import space.kscience.kmath.misc.UnstableKMathAPI
+
 /**
  * Abstraction of writing [MathSyntax] as a string of an actual markup language. Typical implementation should
  * involve traversal of MathSyntax with handling each its subtype.
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun interface SyntaxRenderer {
     /**
      * Renders the [MathSyntax] to [output].
@@ -23,6 +26,7 @@ public fun interface SyntaxRenderer {
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun SyntaxRenderer.renderWithStringBuilder(node: MathSyntax): String {
     val sb = StringBuilder()
     render(node, sb)
diff --git a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/features.kt b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/features.kt
index c09282bb6..c1b513345 100644
--- a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/features.kt
+++ b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/features.kt
@@ -7,6 +7,7 @@ package space.kscience.kmath.ast.rendering
 
 import space.kscience.kmath.ast.rendering.FeaturedMathRenderer.RenderFeature
 import space.kscience.kmath.expressions.MST
+import space.kscience.kmath.misc.UnstableKMathAPI
 import space.kscience.kmath.operations.*
 import kotlin.reflect.KClass
 
@@ -15,11 +16,12 @@ import kotlin.reflect.KClass
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public object PrintSymbolic : RenderFeature {
-    public override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? {
-        if (node !is MST.Symbolic) return null
-        return SymbolSyntax(string = node.value)
-    }
+    public override fun render(renderer: FeaturedMathRenderer, node: MST): SymbolSyntax? =
+        if (node !is MST.Symbolic) null
+        else
+            SymbolSyntax(string = node.value)
 }
 
 /**
@@ -27,25 +29,25 @@ public object PrintSymbolic : RenderFeature {
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public object PrintNumeric : RenderFeature {
-    public override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? {
-        if (node !is MST.Numeric) return null
-        return NumberSyntax(string = node.value.toString())
-    }
+    public override fun render(renderer: FeaturedMathRenderer, node: MST): NumberSyntax? = if (node !is MST.Numeric)
+        null
+    else
+        NumberSyntax(string = node.value.toString())
 }
 
-private fun printSignedNumberString(s: String): MathSyntax {
-    if (s.startsWith('-'))
-        return UnaryMinusSyntax(
-            operation = GroupOperations.MINUS_OPERATION,
-            operand = OperandSyntax(
-                operand = NumberSyntax(string = s.removePrefix("-")),
-                parentheses = true,
-            ),
-        )
-
-    return NumberSyntax(string = s)
-}
+@UnstableKMathAPI
+private fun printSignedNumberString(s: String): MathSyntax = if (s.startsWith('-'))
+    UnaryMinusSyntax(
+        operation = GroupOperations.MINUS_OPERATION,
+        operand = OperandSyntax(
+            operand = NumberSyntax(string = s.removePrefix("-")),
+            parentheses = true,
+        ),
+    )
+else
+    NumberSyntax(string = s)
 
 /**
  * Special printing for numeric types which are printed in form of
@@ -53,9 +55,11 @@ private fun printSignedNumberString(s: String): MathSyntax {
  *
  * @property types The suitable types.
  */
+@UnstableKMathAPI
 public class PrettyPrintFloats(public val types: Set<KClass<out Number>>) : RenderFeature {
     public override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? {
         if (node !is MST.Numeric || node.value::class !in types) return null
+
         val toString = when (val v = node.value) {
             is Float -> v.multiplatformToString()
             is Double -> v.multiplatformToString()
@@ -110,11 +114,13 @@ public class PrettyPrintFloats(public val types: Set<KClass<out Number>>) : Rend
  *
  * @property types The suitable types.
  */
+@UnstableKMathAPI
 public class PrettyPrintIntegers(public val types: Set<KClass<out Number>>) : RenderFeature {
-    public override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? {
-        if (node !is MST.Numeric || node.value::class !in types) return null
-        return printSignedNumberString(node.value.toString())
-    }
+    public override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? =
+        if (node !is MST.Numeric || node.value::class !in types)
+            null
+        else
+            printSignedNumberString(node.value.toString())
 
     public companion object {
         /**
@@ -130,11 +136,13 @@ public class PrettyPrintIntegers(public val types: Set<KClass<out Number>>) : Re
  *
  * @property symbols The allowed symbols.
  */
+@UnstableKMathAPI
 public class PrettyPrintPi(public val symbols: Set<String>) : RenderFeature {
-    public override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? {
-        if (node !is MST.Symbolic || node.value !in symbols) return null
-        return SpecialSymbolSyntax(kind = SpecialSymbolSyntax.Kind.SMALL_PI)
-    }
+    public override fun render(renderer: FeaturedMathRenderer, node: MST): SpecialSymbolSyntax? =
+        if (node !is MST.Symbolic || node.value !in symbols)
+            null
+        else
+            SpecialSymbolSyntax(kind = SpecialSymbolSyntax.Kind.SMALL_PI)
 
     public companion object {
         /**
@@ -150,16 +158,18 @@ public class PrettyPrintPi(public val symbols: Set<String>) : RenderFeature {
  *
  * @param operations the allowed operations. If `null`, any operation is accepted.
  */
+@UnstableKMathAPI
 public abstract class Unary(public val operations: Collection<String>?) : RenderFeature {
     /**
-     * The actual render function.
+     * The actual render function specialized for [MST.Unary].
      */
-    protected abstract fun render0(parent: FeaturedMathRenderer, node: MST.Unary): MathSyntax?
+    protected abstract fun renderUnary(parent: FeaturedMathRenderer, node: MST.Unary): MathSyntax?
 
-    public final override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? {
-        if (node !is MST.Unary || operations != null && node.operation !in operations) return null
-        return render0(renderer, node)
-    }
+    public final override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? =
+        if (node !is MST.Unary || operations != null && node.operation !in operations)
+            null
+        else
+            renderUnary(renderer, node)
 }
 
 /**
@@ -168,164 +178,258 @@ public abstract class Unary(public val operations: Collection<String>?) : Render
  *
  * @property operations the allowed operations. If `null`, any operation is accepted.
  */
+@UnstableKMathAPI
 public abstract class Binary(public val operations: Collection<String>?) : RenderFeature {
     /**
-     * The actual render function.
+     * The actual render function specialized for [MST.Binary].
      */
-    protected abstract fun render0(parent: FeaturedMathRenderer, node: MST.Binary): MathSyntax?
+    protected abstract fun renderBinary(parent: FeaturedMathRenderer, node: MST.Binary): MathSyntax?
 
     public final override fun render(renderer: FeaturedMathRenderer, node: MST): MathSyntax? {
         if (node !is MST.Binary || operations != null && node.operation !in operations) return null
-        return render0(renderer, node)
+        return renderBinary(renderer, node)
     }
 }
 
+/**
+ * Handles binary nodes by producing [BinaryPlusSyntax].
+ */
+@UnstableKMathAPI
 public class BinaryPlus(operations: Collection<String>?) : Binary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Binary): MathSyntax = BinaryPlusSyntax(
-        operation = node.operation,
-        left = OperandSyntax(parent.render(node.left), true),
-        right = OperandSyntax(parent.render(node.right), true),
-    )
+    public override fun renderBinary(parent: FeaturedMathRenderer, node: MST.Binary): BinaryPlusSyntax =
+        BinaryPlusSyntax(
+            operation = node.operation,
+            left = OperandSyntax(parent.render(node.left), true),
+            right = OperandSyntax(parent.render(node.right), true),
+        )
 
     public companion object {
+        /**
+         * The default instance configured with [GroupOperations.PLUS_OPERATION].
+         */
         public val Default: BinaryPlus = BinaryPlus(setOf(GroupOperations.PLUS_OPERATION))
     }
 }
 
+/**
+ * Handles binary nodes by producing [BinaryMinusSyntax].
+ */
+@UnstableKMathAPI
 public class BinaryMinus(operations: Collection<String>?) : Binary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Binary): MathSyntax = BinaryMinusSyntax(
-        operation = node.operation,
-        left = OperandSyntax(operand = parent.render(node.left), parentheses = true),
-        right = OperandSyntax(operand = parent.render(node.right), parentheses = true),
-    )
+    public override fun renderBinary(parent: FeaturedMathRenderer, node: MST.Binary): BinaryMinusSyntax =
+        BinaryMinusSyntax(
+            operation = node.operation,
+            left = OperandSyntax(operand = parent.render(node.left), parentheses = true),
+            right = OperandSyntax(operand = parent.render(node.right), parentheses = true),
+        )
 
     public companion object {
+        /**
+         * The default instance configured with [GroupOperations.MINUS_OPERATION].
+         */
         public val Default: BinaryMinus = BinaryMinus(setOf(GroupOperations.MINUS_OPERATION))
     }
 }
 
+/**
+ * Handles unary nodes by producing [UnaryPlusSyntax].
+ */
+@UnstableKMathAPI
 public class UnaryPlus(operations: Collection<String>?) : Unary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Unary): MathSyntax = UnaryPlusSyntax(
+    public override fun renderUnary(parent: FeaturedMathRenderer, node: MST.Unary): UnaryPlusSyntax = UnaryPlusSyntax(
         operation = node.operation,
         operand = OperandSyntax(operand = parent.render(node.value), parentheses = true),
     )
 
     public companion object {
+        /**
+         * The default instance configured with [GroupOperations.PLUS_OPERATION].
+         */
         public val Default: UnaryPlus = UnaryPlus(setOf(GroupOperations.PLUS_OPERATION))
     }
 }
 
+/**
+ * Handles binary nodes by producing [UnaryMinusSyntax].
+ */
+@UnstableKMathAPI
 public class UnaryMinus(operations: Collection<String>?) : Unary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Unary): MathSyntax = UnaryMinusSyntax(
+    public override fun renderUnary(parent: FeaturedMathRenderer, node: MST.Unary): UnaryMinusSyntax = UnaryMinusSyntax(
         operation = node.operation,
         operand = OperandSyntax(operand = parent.render(node.value), parentheses = true),
     )
 
     public companion object {
+        /**
+         * The default instance configured with [GroupOperations.MINUS_OPERATION].
+         */
         public val Default: UnaryMinus = UnaryMinus(setOf(GroupOperations.MINUS_OPERATION))
     }
 }
 
+/**
+ * Handles binary nodes by producing [FractionSyntax].
+ */
+@UnstableKMathAPI
 public class Fraction(operations: Collection<String>?) : Binary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Binary): MathSyntax = FractionSyntax(
+    public override fun renderBinary(parent: FeaturedMathRenderer, node: MST.Binary): FractionSyntax = FractionSyntax(
         operation = node.operation,
         left = parent.render(node.left),
         right = parent.render(node.right),
     )
 
     public companion object {
+        /**
+         * The default instance configured with [FieldOperations.DIV_OPERATION].
+         */
         public val Default: Fraction = Fraction(setOf(FieldOperations.DIV_OPERATION))
     }
 }
 
+/**
+ * Handles binary nodes by producing [BinaryOperatorSyntax].
+ */
+@UnstableKMathAPI
 public class BinaryOperator(operations: Collection<String>?) : Binary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Binary): MathSyntax = BinaryOperatorSyntax(
-        operation = node.operation,
-        prefix = OperatorNameSyntax(name = node.operation),
-        left = parent.render(node.left),
-        right = parent.render(node.right),
-    )
+    public override fun renderBinary(parent: FeaturedMathRenderer, node: MST.Binary): BinaryOperatorSyntax =
+        BinaryOperatorSyntax(
+            operation = node.operation,
+            prefix = OperatorNameSyntax(name = node.operation),
+            left = parent.render(node.left),
+            right = parent.render(node.right),
+        )
 
     public companion object {
+        /**
+         * The default instance configured with `null`.
+         */
         public val Default: BinaryOperator = BinaryOperator(null)
     }
 }
 
+/**
+ * Handles unary nodes by producing [UnaryOperatorSyntax].
+ */
+@UnstableKMathAPI
 public class UnaryOperator(operations: Collection<String>?) : Unary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Unary): MathSyntax = UnaryOperatorSyntax(
-        operation = node.operation,
-        prefix = OperatorNameSyntax(node.operation),
-        operand = OperandSyntax(parent.render(node.value), true),
-    )
+    public override fun renderUnary(parent: FeaturedMathRenderer, node: MST.Unary): UnaryOperatorSyntax =
+        UnaryOperatorSyntax(
+            operation = node.operation,
+            prefix = OperatorNameSyntax(node.operation),
+            operand = OperandSyntax(parent.render(node.value), true),
+        )
 
     public companion object {
+        /**
+         * The default instance configured with `null`.
+         */
         public val Default: UnaryOperator = UnaryOperator(null)
     }
 }
 
+/**
+ * Handles binary nodes by producing [SuperscriptSyntax].
+ */
+@UnstableKMathAPI
 public class Power(operations: Collection<String>?) : Binary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Binary): MathSyntax = SuperscriptSyntax(
-        operation = node.operation,
-        left = OperandSyntax(parent.render(node.left), true),
-        right = OperandSyntax(parent.render(node.right), true),
-    )
+    public override fun renderBinary(parent: FeaturedMathRenderer, node: MST.Binary): SuperscriptSyntax =
+        SuperscriptSyntax(
+            operation = node.operation,
+            left = OperandSyntax(parent.render(node.left), true),
+            right = OperandSyntax(parent.render(node.right), true),
+        )
 
     public companion object {
+        /**
+         * The default instance configured with [PowerOperations.POW_OPERATION].
+         */
         public val Default: Power = Power(setOf(PowerOperations.POW_OPERATION))
     }
 }
 
+/**
+ * Handles binary nodes by producing [RadicalSyntax] with no index.
+ */
+@UnstableKMathAPI
 public class SquareRoot(operations: Collection<String>?) : Unary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Unary): MathSyntax =
+    public override fun renderUnary(parent: FeaturedMathRenderer, node: MST.Unary): RadicalSyntax =
         RadicalSyntax(operation = node.operation, operand = parent.render(node.value))
 
     public companion object {
+        /**
+         * The default instance configured with [PowerOperations.SQRT_OPERATION].
+         */
         public val Default: SquareRoot = SquareRoot(setOf(PowerOperations.SQRT_OPERATION))
     }
 }
 
+/**
+ * Handles unary nodes by producing [ExponentSyntax].
+ */
+@UnstableKMathAPI
 public class Exponent(operations: Collection<String>?) : Unary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Unary): MathSyntax = ExponentSyntax(
+    public override fun renderUnary(parent: FeaturedMathRenderer, node: MST.Unary): ExponentSyntax = ExponentSyntax(
         operation = node.operation,
         operand = OperandSyntax(operand = parent.render(node.value), parentheses = true),
         useOperatorForm = true,
     )
 
     public companion object {
+        /**
+         * The default instance configured with [ExponentialOperations.EXP_OPERATION].
+         */
         public val Default: Exponent = Exponent(setOf(ExponentialOperations.EXP_OPERATION))
     }
 }
 
+/**
+ * Handles binary nodes by producing [MultiplicationSyntax].
+ */
+@UnstableKMathAPI
 public class Multiplication(operations: Collection<String>?) : Binary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Binary): MathSyntax = MultiplicationSyntax(
-        operation = node.operation,
-        left = OperandSyntax(operand = parent.render(node.left), parentheses = true),
-        right = OperandSyntax(operand = parent.render(node.right), parentheses = true),
-        times = true,
-    )
+    public override fun renderBinary(parent: FeaturedMathRenderer, node: MST.Binary): MultiplicationSyntax =
+        MultiplicationSyntax(
+            operation = node.operation,
+            left = OperandSyntax(operand = parent.render(node.left), parentheses = true),
+            right = OperandSyntax(operand = parent.render(node.right), parentheses = true),
+            times = true,
+        )
 
     public companion object {
-        public val Default: Multiplication = Multiplication(setOf(
-            RingOperations.TIMES_OPERATION,
-        ))
+        /**
+         * The default instance configured with [RingOperations.TIMES_OPERATION].
+         */
+        public val Default: Multiplication = Multiplication(setOf(RingOperations.TIMES_OPERATION))
     }
 }
 
+/**
+ * Handles binary nodes by producing inverse [UnaryOperatorSyntax] (like *sin<sup>-1</sup>*) with removing the `a`
+ * prefix of operation ID.
+ */
+@UnstableKMathAPI
 public class InverseTrigonometricOperations(operations: Collection<String>?) : Unary(operations) {
-    public override fun render0(parent: FeaturedMathRenderer, node: MST.Unary): MathSyntax = UnaryOperatorSyntax(
-        operation = node.operation,
-        prefix = SuperscriptSyntax(
-            operation = PowerOperations.POW_OPERATION,
-            left = OperatorNameSyntax(name = node.operation.removePrefix("a")),
-            right = UnaryMinusSyntax(
-                operation = GroupOperations.MINUS_OPERATION,
-                operand = OperandSyntax(operand = NumberSyntax(string = "1"), parentheses = true),
+    public override fun renderUnary(parent: FeaturedMathRenderer, node: MST.Unary): UnaryOperatorSyntax =
+        UnaryOperatorSyntax(
+            operation = node.operation,
+            prefix = SuperscriptSyntax(
+                operation = PowerOperations.POW_OPERATION,
+                left = OperatorNameSyntax(name = node.operation.removePrefix("a")),
+                right = UnaryMinusSyntax(
+                    operation = GroupOperations.MINUS_OPERATION,
+                    operand = OperandSyntax(operand = NumberSyntax(string = "1"), parentheses = true),
+                ),
             ),
-        ),
-        operand = OperandSyntax(operand = parent.render(node.value), parentheses = true),
-    )
+            operand = OperandSyntax(operand = parent.render(node.value), parentheses = true),
+        )
 
     public companion object {
+        /**
+         * The default instance configured with [TrigonometricOperations.ACOS_OPERATION],
+         * [TrigonometricOperations.ASIN_OPERATION], [TrigonometricOperations.ATAN_OPERATION],
+         * [ExponentialOperations.ACOSH_OPERATION], [ExponentialOperations.ASINH_OPERATION], and
+         * [ExponentialOperations.ATANH_OPERATION].
+         */
         public val Default: InverseTrigonometricOperations = InverseTrigonometricOperations(setOf(
             TrigonometricOperations.ACOS_OPERATION,
             TrigonometricOperations.ASIN_OPERATION,
diff --git a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/stages.kt b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/stages.kt
index a08f089f1..7eb75b9ff 100644
--- a/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/stages.kt
+++ b/kmath-ast/src/commonMain/kotlin/space/kscience/kmath/ast/rendering/stages.kt
@@ -5,6 +5,7 @@
 
 package space.kscience.kmath.ast.rendering
 
+import space.kscience.kmath.misc.UnstableKMathAPI
 import space.kscience.kmath.operations.FieldOperations
 import space.kscience.kmath.operations.GroupOperations
 import space.kscience.kmath.operations.PowerOperations
@@ -15,6 +16,7 @@ import space.kscience.kmath.operations.RingOperations
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public object BetterMultiplication : FeaturedMathRendererWithPostProcess.PostProcessStage {
     public override fun perform(node: MathSyntax): Unit = when (node) {
         is NumberSyntax -> Unit
@@ -88,6 +90,7 @@ public object BetterMultiplication : FeaturedMathRendererWithPostProcess.PostPro
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public object BetterExponent : FeaturedMathRendererWithPostProcess.PostProcessStage {
     private fun perform0(node: MathSyntax): Boolean {
         return when (node) {
@@ -129,6 +132,7 @@ public object BetterExponent : FeaturedMathRendererWithPostProcess.PostProcessSt
  * @property precedenceFunction Returns the precedence number for syntax node. Higher number is lower priority.
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public class SimplifyParentheses(public val precedenceFunction: (MathSyntax) -> Int) :
     FeaturedMathRendererWithPostProcess.PostProcessStage {
     public override fun perform(node: MathSyntax): Unit = when (node) {
diff --git a/kmath-ast/src/commonTest/kotlin/space/kscience/kmath/ast/ParserPrecedenceTest.kt b/kmath-ast/src/commonTest/kotlin/space/kscience/kmath/ast/ParserPrecedenceTest.kt
index ca3a95bc8..67d77839a 100644
--- a/kmath-ast/src/commonTest/kotlin/space/kscience/kmath/ast/ParserPrecedenceTest.kt
+++ b/kmath-ast/src/commonTest/kotlin/space/kscience/kmath/ast/ParserPrecedenceTest.kt
@@ -5,7 +5,6 @@
 
 package space.kscience.kmath.ast
 
-import space.kscience.kmath.ast.parseMath
 import space.kscience.kmath.expressions.evaluate
 import space.kscience.kmath.operations.DoubleField
 import kotlin.test.Test
diff --git a/kmath-ast/src/commonTest/kotlin/space/kscience/kmath/ast/rendering/TestUtils.kt b/kmath-ast/src/commonTest/kotlin/space/kscience/kmath/ast/rendering/TestUtils.kt
index 7c9400532..bf87b6fd0 100644
--- a/kmath-ast/src/commonTest/kotlin/space/kscience/kmath/ast/rendering/TestUtils.kt
+++ b/kmath-ast/src/commonTest/kotlin/space/kscience/kmath/ast/rendering/TestUtils.kt
@@ -30,17 +30,17 @@ internal object TestUtils {
     )
 
     internal fun testMathML(mst: MST, expectedMathML: String) = assertEquals(
-        expected = "<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow>$expectedMathML</mrow></math>",
+        expected = "<math xmlns=\"https://www.w3.org/1998/Math/MathML\"><mrow>$expectedMathML</mrow></math>",
         actual = mathML(mst),
     )
 
     internal fun testMathML(expression: String, expectedMathML: String) = assertEquals(
-        expected = "<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow>$expectedMathML</mrow></math>",
+        expected = "<math xmlns=\"https://www.w3.org/1998/Math/MathML\"><mrow>$expectedMathML</mrow></math>",
         actual = mathML(expression.parseMath()),
     )
 
     internal fun testMathML(expression: MathSyntax, expectedMathML: String) = assertEquals(
-        expected = "<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow>$expectedMathML</mrow></math>",
+        expected = "<math xmlns=\"https://www.w3.org/1998/Math/MathML\"><mrow>$expectedMathML</mrow></math>",
         actual = MathMLSyntaxRenderer.renderWithStringBuilder(expression),
     )
 }
diff --git a/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/internal/webassembly/nonDeclarations.WebAssembly.kt b/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/internal/webassembly/nonDeclarations.WebAssembly.kt
index 59733299a..c5023c384 100644
--- a/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/internal/webassembly/nonDeclarations.WebAssembly.kt
+++ b/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/internal/webassembly/nonDeclarations.WebAssembly.kt
@@ -3,7 +3,8 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-@file:Suppress("INTERFACE_WITH_SUPERCLASS",
+@file:Suppress(
+    "INTERFACE_WITH_SUPERCLASS",
     "OVERRIDING_FINAL_MEMBER",
     "RETURN_TYPE_MISMATCH_ON_OVERRIDE",
     "CONFLICTING_OVERLOADS",
diff --git a/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/wasm/internal/WasmBuilder.kt b/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/wasm/internal/WasmBuilder.kt
index bd2b340a0..8fd3c9fb9 100644
--- a/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/wasm/internal/WasmBuilder.kt
+++ b/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/wasm/internal/WasmBuilder.kt
@@ -26,7 +26,7 @@ internal sealed class WasmBuilder<T>(
     val keys: MutableList<String> = mutableListOf()
     lateinit var ctx: BinaryenModule
 
-    open fun visitSymbolic(mst: MST.Symbolic): ExpressionRef {
+    open fun visitSymbolic(mst: Symbolic): ExpressionRef {
         try {
             algebra.bindSymbol(mst.value)
         } catch (ignored: Throwable) {
diff --git a/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/wasm/wasm.kt b/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/wasm/wasm.kt
index d44c4e49d..394a0567e 100644
--- a/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/wasm/wasm.kt
+++ b/kmath-ast/src/jsMain/kotlin/space/kscience/kmath/wasm/wasm.kt
@@ -10,6 +10,7 @@ import space.kscience.kmath.expressions.Expression
 import space.kscience.kmath.expressions.MST
 import space.kscience.kmath.expressions.invoke
 import space.kscience.kmath.misc.Symbol
+import space.kscience.kmath.misc.UnstableKMathAPI
 import space.kscience.kmath.operations.DoubleField
 import space.kscience.kmath.operations.IntRing
 import space.kscience.kmath.wasm.internal.DoubleWasmBuilder
@@ -20,6 +21,7 @@ import space.kscience.kmath.wasm.internal.IntWasmBuilder
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun DoubleField.expression(mst: MST): Expression<Double> =
     DoubleWasmBuilder(mst).instance
 
@@ -28,6 +30,7 @@ public fun DoubleField.expression(mst: MST): Expression<Double> =
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun IntRing.expression(mst: MST): Expression<Int> =
     IntWasmBuilder(mst).instance
 
@@ -36,6 +39,7 @@ public fun IntRing.expression(mst: MST): Expression<Int> =
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun MST.compileToExpression(algebra: IntRing): Expression<Int> = compileWith(algebra)
 
 
@@ -44,6 +48,7 @@ public fun MST.compileToExpression(algebra: IntRing): Expression<Int> = compileW
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun MST.compile(algebra: IntRing, arguments: Map<Symbol, Int>): Int =
     compileToExpression(algebra).invoke(arguments)
 
@@ -53,6 +58,7 @@ public fun MST.compile(algebra: IntRing, arguments: Map<Symbol, Int>): Int =
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun MST.compile(algebra: IntRing, vararg arguments: Pair<Symbol, Int>): Int =
     compileToExpression(algebra)(*arguments)
 
@@ -61,6 +67,7 @@ public fun MST.compile(algebra: IntRing, vararg arguments: Pair<Symbol, Int>): I
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun MST.compileToExpression(algebra: DoubleField): Expression<Double> = compileWith(algebra)
 
 
@@ -69,6 +76,7 @@ public fun MST.compileToExpression(algebra: DoubleField): Expression<Double> = c
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun MST.compile(algebra: DoubleField, arguments: Map<Symbol, Double>): Double =
     compileToExpression(algebra).invoke(arguments)
 
@@ -78,5 +86,6 @@ public fun MST.compile(algebra: DoubleField, arguments: Map<Symbol, Double>): Do
  *
  * @author Iaroslav Postovalov
  */
+@UnstableKMathAPI
 public fun MST.compile(algebra: DoubleField, vararg arguments: Pair<Symbol, Double>): Double =
     compileToExpression(algebra).invoke(*arguments)
diff --git a/kmath-ast/src/jvmMain/kotlin/space/kscience/kmath/asm/internal/AsmBuilder.kt b/kmath-ast/src/jvmMain/kotlin/space/kscience/kmath/asm/internal/AsmBuilder.kt
index bdd8f52b6..39ebf049d 100644
--- a/kmath-ast/src/jvmMain/kotlin/space/kscience/kmath/asm/internal/AsmBuilder.kt
+++ b/kmath-ast/src/jvmMain/kotlin/space/kscience/kmath/asm/internal/AsmBuilder.kt
@@ -342,8 +342,8 @@ internal class AsmBuilder<T>(
         val MAP_INTRINSICS_TYPE: Type by lazy { getObjectType("space/kscience/kmath/asm/internal/MapIntrinsics") }
 
         /**
-         * ASM Type for [kscience.kmath.expressions.Symbol].
+         * ASM Type for [space.kscience.kmath.misc.Symbol].
          */
-        val SYMBOL_TYPE: Type by lazy { getObjectType("space/kscience/kmath/expressions/Symbol") }
+        val SYMBOL_TYPE: Type by lazy { getObjectType("space/kscience/kmath/misc/Symbol") }
     }
 }
diff --git a/kmath-ast/src/jvmMain/kotlin/space/kscience/kmath/asm/internal/codegenUtils.kt b/kmath-ast/src/jvmMain/kotlin/space/kscience/kmath/asm/internal/codegenUtils.kt
index 560780f99..cfac59847 100644
--- a/kmath-ast/src/jvmMain/kotlin/space/kscience/kmath/asm/internal/codegenUtils.kt
+++ b/kmath-ast/src/jvmMain/kotlin/space/kscience/kmath/asm/internal/codegenUtils.kt
@@ -52,7 +52,7 @@ internal inline fun MethodVisitor.instructionAdapter(block: InstructionAdapter.(
  *
  * @author Iaroslav Postovalov
  */
-internal fun MethodVisitor.label(): Label = Label().also { visitLabel(it) }
+internal fun MethodVisitor.label(): Label = Label().also(::visitLabel)
 
 /**
  * Creates a class name for [Expression] subclassed to implement [mst] provided.