diff --git a/CHANGELOG.md b/CHANGELOG.md
index e542d210c..840733d92 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,6 +32,7 @@
 - Optimized dot product for buffer matrices moved to `kmath-for-real`
 - EjmlMatrix context is an object
 - Matrix LUP `inverse` renamed to `inverseWithLUP`
+- `NumericAlgebra` moved outside of regular algebra chain (`Ring` no longer implements it).
 
 ### Deprecated
 
diff --git a/build.gradle.kts b/build.gradle.kts
index 90a39c531..d171bd608 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -4,7 +4,7 @@ plugins {
     id("ru.mipt.npm.project")
 }
 
-internal val kmathVersion: String by extra("0.2.0-dev-4")
+internal val kmathVersion: String by extra("0.2.0-dev-5")
 internal val bintrayRepo: String by extra("kscience")
 internal val githubProject: String by extra("kmath")
 
diff --git a/examples/src/benchmarks/kotlin/kscience/kmath/benchmarks/LargeNDBenchmark.kt b/examples/src/benchmarks/kotlin/kscience/kmath/benchmarks/LargeNDBenchmark.kt
new file mode 100644
index 000000000..395fde619
--- /dev/null
+++ b/examples/src/benchmarks/kotlin/kscience/kmath/benchmarks/LargeNDBenchmark.kt
@@ -0,0 +1,25 @@
+package kscience.kmath.benchmarks
+
+import kscience.kmath.structures.NDField
+import org.openjdk.jmh.annotations.Benchmark
+import org.openjdk.jmh.annotations.Scope
+import org.openjdk.jmh.annotations.State
+import org.openjdk.jmh.infra.Blackhole
+import kotlin.random.Random
+
+@State(Scope.Benchmark)
+class LargeNDBenchmark {
+    val arraySize = 10000
+    val RANDOM = Random(222)
+    val src1 = DoubleArray(arraySize) { RANDOM.nextDouble() }
+    val src2 = DoubleArray(arraySize) { RANDOM.nextDouble() }
+    val field = NDField.real(arraySize)
+    val kmathArray1 = field.produce { (a) -> src1[a] }
+    val kmathArray2 = field.produce { (a) -> src2[a] }
+
+    @Benchmark
+    fun test10000(bh: Blackhole) {
+        bh.consume(field.add(kmathArray1, kmathArray2))
+    }
+
+}
\ No newline at end of file
diff --git a/examples/src/main/kotlin/kscience/kmath/stat/DistributionBenchmark.kt b/examples/src/main/kotlin/kscience/kmath/stat/DistributionBenchmark.kt
index ef554aeff..99d3cd504 100644
--- a/examples/src/main/kotlin/kscience/kmath/stat/DistributionBenchmark.kt
+++ b/examples/src/main/kotlin/kscience/kmath/stat/DistributionBenchmark.kt
@@ -3,7 +3,6 @@ package kscience.kmath.commons.prob
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.async
 import kotlinx.coroutines.runBlocking
-import kscience.kmath.chains.BlockingRealChain
 import kscience.kmath.stat.*
 import org.apache.commons.rng.sampling.distribution.ZigguratNormalizedGaussianSampler
 import org.apache.commons.rng.simple.RandomSource
@@ -13,7 +12,7 @@ import java.time.Instant
 private fun runChain(): Duration {
     val generator = RandomGenerator.fromSource(RandomSource.MT, 123L)
     val normal = Distribution.normal(NormalSamplerMethod.Ziggurat)
-    val chain = normal.sample(generator) as BlockingRealChain
+    val chain = normal.sample(generator)
     val startTime = Instant.now()
     var sum = 0.0
 
diff --git a/examples/src/main/kotlin/kscience/kmath/structures/ComplexND.kt b/examples/src/main/kotlin/kscience/kmath/structures/ComplexND.kt
index aa4b10ef2..b69590473 100644
--- a/examples/src/main/kotlin/kscience/kmath/structures/ComplexND.kt
+++ b/examples/src/main/kotlin/kscience/kmath/structures/ComplexND.kt
@@ -11,7 +11,7 @@ fun main() {
     val n = 1000
 
     val realField = NDField.real(dim, dim)
-    val complexField = NDField.complex(dim, dim)
+    val complexField: ComplexNDField = NDField.complex(dim, dim)
 
     val realTime = measureTimeMillis {
         realField {
diff --git a/examples/src/main/kotlin/kscience/kmath/structures/NDField.kt b/examples/src/main/kotlin/kscience/kmath/structures/NDField.kt
index 778d811fd..b5130c92b 100644
--- a/examples/src/main/kotlin/kscience/kmath/structures/NDField.kt
+++ b/examples/src/main/kotlin/kscience/kmath/structures/NDField.kt
@@ -33,7 +33,7 @@ fun main() {
     measureAndPrint("Automatic field addition") {
         autoField {
             var res: NDBuffer<Double> = one
-            repeat(n) { res += number(1.0) }
+            repeat(n) { res += 1.0 }
         }
     }
 
@@ -45,14 +45,14 @@ fun main() {
     measureAndPrint("Specialized addition") {
         specializedField {
             var res: NDBuffer<Double> = one
-            repeat(n) { res += one }
+            repeat(n) { res += 1.0 }
         }
     }
 
     measureAndPrint("Nd4j specialized addition") {
         nd4jField {
             var res = one
-            repeat(n) { res += one }
+            repeat(n) { res += 1.0 }
         }
     }
 
@@ -73,7 +73,7 @@ fun main() {
         genericField {
             var res: NDBuffer<Double> = one
             repeat(n) {
-                res += one // couldn't avoid using `one` due to resolution ambiguity }
+                res += 1.0 // couldn't avoid using `one` due to resolution ambiguity }
             }
         }
     }
diff --git a/kmath-ast/src/commonMain/kotlin/kscience/kmath/ast/MstAlgebra.kt b/kmath-ast/src/commonMain/kotlin/kscience/kmath/ast/MstAlgebra.kt
index 80b164a7c..eadbc85ee 100644
--- a/kmath-ast/src/commonMain/kotlin/kscience/kmath/ast/MstAlgebra.kt
+++ b/kmath-ast/src/commonMain/kotlin/kscience/kmath/ast/MstAlgebra.kt
@@ -1,5 +1,6 @@
 package kscience.kmath.ast
 
+import kscience.kmath.misc.UnstableKMathAPI
 import kscience.kmath.operations.*
 
 /**
@@ -25,8 +26,11 @@ public object MstSpace : Space<MST>, NumericAlgebra<MST> {
     public override fun number(value: Number): MST.Numeric = MstAlgebra.number(value)
     public override fun symbol(value: String): MST.Symbolic = MstAlgebra.symbol(value)
     public override fun add(a: MST, b: MST): MST.Binary = binaryOperationFunction(SpaceOperations.PLUS_OPERATION)(a, b)
-    public override operator fun MST.unaryPlus(): MST.Unary = unaryOperationFunction(SpaceOperations.PLUS_OPERATION)(this)
-    public override operator fun MST.unaryMinus(): MST.Unary = unaryOperationFunction(SpaceOperations.MINUS_OPERATION)(this)
+    public override operator fun MST.unaryPlus(): MST.Unary =
+        unaryOperationFunction(SpaceOperations.PLUS_OPERATION)(this)
+
+    public override operator fun MST.unaryMinus(): MST.Unary =
+        unaryOperationFunction(SpaceOperations.MINUS_OPERATION)(this)
 
     public override operator fun MST.minus(b: MST): MST.Binary =
         binaryOperationFunction(SpaceOperations.MINUS_OPERATION)(this, b)
@@ -44,7 +48,8 @@ public object MstSpace : Space<MST>, NumericAlgebra<MST> {
 /**
  * [Ring] over [MST] nodes.
  */
-public object MstRing : Ring<MST>, NumericAlgebra<MST> {
+@OptIn(UnstableKMathAPI::class)
+public object MstRing : Ring<MST>, RingWithNumbers<MST> {
     public override val zero: MST.Numeric
         get() = MstSpace.zero
 
@@ -54,7 +59,9 @@ public object MstRing : Ring<MST>, NumericAlgebra<MST> {
     public override fun symbol(value: String): MST.Symbolic = MstSpace.symbol(value)
     public override fun add(a: MST, b: MST): MST.Binary = MstSpace.add(a, b)
     public override fun multiply(a: MST, k: Number): MST.Binary = MstSpace.multiply(a, k)
-    public override fun multiply(a: MST, b: MST): MST.Binary = binaryOperationFunction(RingOperations.TIMES_OPERATION)(a, b)
+    public override fun multiply(a: MST, b: MST): MST.Binary =
+        binaryOperationFunction(RingOperations.TIMES_OPERATION)(a, b)
+
     public override operator fun MST.unaryPlus(): MST.Unary = MstSpace { +this@unaryPlus }
     public override operator fun MST.unaryMinus(): MST.Unary = MstSpace { -this@unaryMinus }
     public override operator fun MST.minus(b: MST): MST.Binary = MstSpace { this@minus - b }
@@ -69,7 +76,8 @@ public object MstRing : Ring<MST>, NumericAlgebra<MST> {
 /**
  * [Field] over [MST] nodes.
  */
-public object MstField : Field<MST> {
+@OptIn(UnstableKMathAPI::class)
+public object MstField : Field<MST>, RingWithNumbers<MST> {
     public override val zero: MST.Numeric
         get() = MstRing.zero
 
@@ -81,7 +89,9 @@ public object MstField : Field<MST> {
     public override fun add(a: MST, b: MST): MST.Binary = MstRing.add(a, b)
     public override fun multiply(a: MST, k: Number): MST.Binary = MstRing.multiply(a, k)
     public override fun multiply(a: MST, b: MST): MST.Binary = MstRing.multiply(a, b)
-    public override fun divide(a: MST, b: MST): MST.Binary = binaryOperationFunction(FieldOperations.DIV_OPERATION)(a, b)
+    public override fun divide(a: MST, b: MST): MST.Binary =
+        binaryOperationFunction(FieldOperations.DIV_OPERATION)(a, b)
+
     public override operator fun MST.unaryPlus(): MST.Unary = MstRing { +this@unaryPlus }
     public override operator fun MST.unaryMinus(): MST.Unary = MstRing { -this@unaryMinus }
     public override operator fun MST.minus(b: MST): MST.Binary = MstRing { this@minus - b }
@@ -89,13 +99,14 @@ public object MstField : Field<MST> {
     public override fun binaryOperationFunction(operation: String): (left: MST, right: MST) -> MST.Binary =
         MstRing.binaryOperationFunction(operation)
 
-    public override fun unaryOperationFunction(operation: String): (arg: MST) -> MST.Unary = MstRing.unaryOperationFunction(operation)
+    public override fun unaryOperationFunction(operation: String): (arg: MST) -> MST.Unary =
+        MstRing.unaryOperationFunction(operation)
 }
 
 /**
  * [ExtendedField] over [MST] nodes.
  */
-public object MstExtendedField : ExtendedField<MST> {
+public object MstExtendedField : ExtendedField<MST>, NumericAlgebra<MST> {
     public override val zero: MST.Numeric
         get() = MstField.zero
 
@@ -103,6 +114,7 @@ public object MstExtendedField : ExtendedField<MST> {
         get() = MstField.one
 
     public override fun symbol(value: String): MST.Symbolic = MstField.symbol(value)
+    public override fun number(value: Number): MST.Numeric = MstRing.number(value)
     public override fun sin(arg: MST): MST.Unary = unaryOperationFunction(TrigonometricOperations.SIN_OPERATION)(arg)
     public override fun cos(arg: MST): MST.Unary = unaryOperationFunction(TrigonometricOperations.COS_OPERATION)(arg)
     public override fun tan(arg: MST): MST.Unary = unaryOperationFunction(TrigonometricOperations.TAN_OPERATION)(arg)
@@ -132,5 +144,6 @@ public object MstExtendedField : ExtendedField<MST> {
     public override fun binaryOperationFunction(operation: String): (left: MST, right: MST) -> MST.Binary =
         MstField.binaryOperationFunction(operation)
 
-    public override fun unaryOperationFunction(operation: String): (arg: MST) -> MST.Unary = MstField.unaryOperationFunction(operation)
+    public override fun unaryOperationFunction(operation: String): (arg: MST) -> MST.Unary =
+        MstField.unaryOperationFunction(operation)
 }
diff --git a/kmath-commons/src/main/kotlin/kscience/kmath/commons/expressions/DerivativeStructureExpression.kt b/kmath-commons/src/main/kotlin/kscience/kmath/commons/expressions/DerivativeStructureExpression.kt
index 345babe8b..2912ddc4c 100644
--- a/kmath-commons/src/main/kotlin/kscience/kmath/commons/expressions/DerivativeStructureExpression.kt
+++ b/kmath-commons/src/main/kotlin/kscience/kmath/commons/expressions/DerivativeStructureExpression.kt
@@ -1,7 +1,9 @@
 package kscience.kmath.commons.expressions
 
 import kscience.kmath.expressions.*
+import kscience.kmath.misc.UnstableKMathAPI
 import kscience.kmath.operations.ExtendedField
+import kscience.kmath.operations.RingWithNumbers
 import org.apache.commons.math3.analysis.differentiation.DerivativeStructure
 
 /**
@@ -10,15 +12,18 @@ import org.apache.commons.math3.analysis.differentiation.DerivativeStructure
  * @property order The derivation order.
  * @property bindings The map of bindings values. All bindings are considered free parameters
  */
+@OptIn(UnstableKMathAPI::class)
 public class DerivativeStructureField(
     public val order: Int,
     bindings: Map<Symbol, Double>,
-) : ExtendedField<DerivativeStructure>, ExpressionAlgebra<Double, DerivativeStructure> {
+) : ExtendedField<DerivativeStructure>, ExpressionAlgebra<Double, DerivativeStructure>, RingWithNumbers<DerivativeStructure> {
     public val numberOfVariables: Int = bindings.size
 
     public override val zero: DerivativeStructure by lazy { DerivativeStructure(numberOfVariables, order) }
     public override val one: DerivativeStructure by lazy { DerivativeStructure(numberOfVariables, order, 1.0) }
 
+    override fun number(value: Number): DerivativeStructure = const(value.toDouble())
+
     /**
      * A class that implements both [DerivativeStructure] and a [Symbol]
      */
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/FunctionalExpressionAlgebra.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/FunctionalExpressionAlgebra.kt
index afbaf16e1..880a4e34c 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/FunctionalExpressionAlgebra.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/FunctionalExpressionAlgebra.kt
@@ -7,8 +7,9 @@ import kscience.kmath.operations.*
  *
  * @param algebra The algebra to provide for Expressions built.
  */
-public abstract class FunctionalExpressionAlgebra<T, A : Algebra<T>>(public val algebra: A) :
-    ExpressionAlgebra<T, Expression<T>> {
+public abstract class FunctionalExpressionAlgebra<T, A : Algebra<T>>(
+    public val algebra: A,
+) : ExpressionAlgebra<T, Expression<T>> {
     /**
      * Builds an Expression of constant expression which does not depend on arguments.
      */
@@ -42,8 +43,9 @@ public abstract class FunctionalExpressionAlgebra<T, A : Algebra<T>>(public val
 /**
  * A context class for [Expression] construction for [Space] algebras.
  */
-public open class FunctionalExpressionSpace<T, A : Space<T>>(algebra: A) :
-    FunctionalExpressionAlgebra<T, A>(algebra), Space<Expression<T>> {
+public open class FunctionalExpressionSpace<T, A : Space<T>>(
+    algebra: A,
+) : FunctionalExpressionAlgebra<T, A>(algebra), Space<Expression<T>> {
     public override val zero: Expression<T> get() = const(algebra.zero)
 
     /**
@@ -71,8 +73,9 @@ public open class FunctionalExpressionSpace<T, A : Space<T>>(algebra: A) :
         super<FunctionalExpressionAlgebra>.binaryOperationFunction(operation)
 }
 
-public open class FunctionalExpressionRing<T, A>(algebra: A) : FunctionalExpressionSpace<T, A>(algebra),
-    Ring<Expression<T>> where  A : Ring<T>, A : NumericAlgebra<T> {
+public open class FunctionalExpressionRing<T, A : Ring<T>>(
+    algebra: A,
+) : FunctionalExpressionSpace<T, A>(algebra), Ring<Expression<T>> {
     public override val one: Expression<T>
         get() = const(algebra.one)
 
@@ -92,9 +95,8 @@ public open class FunctionalExpressionRing<T, A>(algebra: A) : FunctionalExpress
         super<FunctionalExpressionSpace>.binaryOperationFunction(operation)
 }
 
-public open class FunctionalExpressionField<T, A>(algebra: A) :
-    FunctionalExpressionRing<T, A>(algebra), Field<Expression<T>>
-        where A : Field<T>, A : NumericAlgebra<T> {
+public open class FunctionalExpressionField<T, A : Field<T>>(algebra: A) :
+    FunctionalExpressionRing<T, A>(algebra), Field<Expression<T>> {
     /**
      * Builds an Expression of division an expression by another one.
      */
@@ -111,9 +113,12 @@ public open class FunctionalExpressionField<T, A>(algebra: A) :
         super<FunctionalExpressionRing>.binaryOperationFunction(operation)
 }
 
-public open class FunctionalExpressionExtendedField<T, A>(algebra: A) :
-    FunctionalExpressionField<T, A>(algebra),
-    ExtendedField<Expression<T>> where A : ExtendedField<T>, A : NumericAlgebra<T> {
+public open class FunctionalExpressionExtendedField<T, A : ExtendedField<T>>(
+    algebra: A,
+) : FunctionalExpressionField<T, A>(algebra), ExtendedField<Expression<T>> {
+
+    override fun number(value: Number): Expression<T> = const(algebra.number(value))
+
     public override fun sin(arg: Expression<T>): Expression<T> =
         unaryOperationFunction(TrigonometricOperations.SIN_OPERATION)(arg)
 
@@ -135,7 +140,8 @@ public open class FunctionalExpressionExtendedField<T, A>(algebra: A) :
     public override fun exp(arg: Expression<T>): Expression<T> =
         unaryOperationFunction(ExponentialOperations.EXP_OPERATION)(arg)
 
-    public override fun ln(arg: Expression<T>): Expression<T> = unaryOperationFunction(ExponentialOperations.LN_OPERATION)(arg)
+    public override fun ln(arg: Expression<T>): Expression<T> =
+        unaryOperationFunction(ExponentialOperations.LN_OPERATION)(arg)
 
     public override fun unaryOperationFunction(operation: String): (arg: Expression<T>) -> Expression<T> =
         super<FunctionalExpressionField>.unaryOperationFunction(operation)
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/SimpleAutoDiff.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/SimpleAutoDiff.kt
index e8a894d23..0621e82bd 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/SimpleAutoDiff.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/SimpleAutoDiff.kt
@@ -1,6 +1,7 @@
 package kscience.kmath.expressions
 
 import kscience.kmath.linear.Point
+import kscience.kmath.misc.UnstableKMathAPI
 import kscience.kmath.operations.*
 import kscience.kmath.structures.asBuffer
 import kotlin.contracts.InvocationKind
@@ -79,10 +80,11 @@ public fun <T : Any, F : Field<T>> F.simpleAutoDiff(
 /**
  * Represents field in context of which functions can be derived.
  */
+@OptIn(UnstableKMathAPI::class)
 public open class SimpleAutoDiffField<T : Any, F : Field<T>>(
     public val context: F,
     bindings: Map<Symbol, T>,
-) : Field<AutoDiffValue<T>>, ExpressionAlgebra<T, AutoDiffValue<T>> {
+) : Field<AutoDiffValue<T>>, ExpressionAlgebra<T, AutoDiffValue<T>>, RingWithNumbers<AutoDiffValue<T>> {
     public override val zero: AutoDiffValue<T>
         get() = const(context.zero)
 
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/linear/MatrixFeatures.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/linear/MatrixFeatures.kt
index 767b58eba..1f93309a6 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/linear/MatrixFeatures.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/linear/MatrixFeatures.kt
@@ -1,5 +1,7 @@
 package kscience.kmath.linear
 
+import kscience.kmath.structures.Matrix
+
 /**
  * A marker interface representing some properties of matrices or additional transformations of them. Features are used
  * to optimize matrix operations performance in some cases or retrieve the APIs.
@@ -30,7 +32,7 @@ public interface InverseMatrixFeature<T : Any> : MatrixFeature {
     /**
      * The inverse matrix of the matrix that owns this feature.
      */
-    public val inverse: FeaturedMatrix<T>
+    public val inverse: Matrix<T>
 }
 
 /**
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Algebra.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Algebra.kt
index 24b417860..2bafd377e 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Algebra.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Algebra.kt
@@ -88,85 +88,6 @@ public interface Algebra<T> {
     public fun binaryOperation(operation: String, left: T, right: T): T = binaryOperationFunction(operation)(left, right)
 }
 
-/**
- * An algebraic structure where elements can have numeric representation.
- *
- * @param T the type of element of this structure.
- */
-public interface NumericAlgebra<T> : Algebra<T> {
-    /**
-     * Wraps a number to [T] object.
-     *
-     * @param value the number to wrap.
-     * @return an object.
-     */
-    public fun number(value: Number): T
-
-    /**
-     * Dynamically dispatches a binary operation with the certain name with numeric first argument.
-     *
-     * This function must follow two properties:
-     *
-     * 1. In case if operation is not defined in the structure, the function throws [kotlin.IllegalStateException].
-     * 2. This function is symmetric with the other [leftSideNumberOperation] overload:
-     * i.e. `leftSideNumberOperationFunction(a)(b, c) == leftSideNumberOperation(a, b)`.
-     *
-     * @param operation the name of operation.
-     * @return an operation.
-     */
-    public fun leftSideNumberOperationFunction(operation: String): (left: Number, right: T) -> T =
-        { l, r -> binaryOperationFunction(operation)(number(l), r) }
-
-    /**
-     * Dynamically invokes a binary operation with the certain name with numeric first argument.
-     *
-     * This function must follow two properties:
-     *
-     * 1. In case if operation is not defined in the structure, the function throws [kotlin.IllegalStateException].
-     * 2. This function is symmetric with second [leftSideNumberOperation] overload:
-     * i.e. `leftSideNumberOperationFunction(a)(b, c) == leftSideNumberOperation(a, b, c)`.
-     *
-     * @param operation the name of operation.
-     * @param left the first argument of operation.
-     * @param right the second argument of operation.
-     * @return a result of operation.
-     */
-    public fun leftSideNumberOperation(operation: String, left: Number, right: T): T =
-        leftSideNumberOperationFunction(operation)(left, right)
-
-    /**
-     * Dynamically dispatches a binary operation with the certain name with numeric first argument.
-     *
-     * This function must follow two properties:
-     *
-     * 1. In case if operation is not defined in the structure, the function throws [kotlin.IllegalStateException].
-     * 2. This function is symmetric with the other [rightSideNumberOperationFunction] overload:
-     * i.e. `rightSideNumberOperationFunction(a)(b, c) == leftSideNumberOperation(a, b, c)`.
-     *
-     * @param operation the name of operation.
-     * @return an operation.
-     */
-    public fun rightSideNumberOperationFunction(operation: String): (left: T, right: Number) -> T =
-        { l, r -> binaryOperationFunction(operation)(l, number(r)) }
-
-    /**
-     * Dynamically invokes a binary operation with the certain name with numeric second argument.
-     *
-     * This function must follow two properties:
-     *
-     * 1. In case if operation is not defined in the structure, the function throws [kotlin.IllegalStateException].
-     * 2. This function is symmetric with the other [rightSideNumberOperationFunction] overload:
-     * i.e. `rightSideNumberOperationFunction(a)(b, c) == rightSideNumberOperation(a, b, c)`.
-     *
-     * @param operation the name of operation.
-     * @param left the first argument of operation.
-     * @param right the second argument of operation.
-     * @return a result of operation.
-     */
-    public fun rightSideNumberOperation(operation: String, left: T, right: Number): T =
-        rightSideNumberOperationFunction(operation)(left, right)
-}
-
 /**
  * Call a block with an [Algebra] as receiver.
  */
@@ -341,47 +262,11 @@ public interface RingOperations<T> : SpaceOperations<T> {
  *
  * @param T the type of element of this ring.
  */
-public interface Ring<T> : Space<T>, RingOperations<T>, NumericAlgebra<T> {
+public interface Ring<T> : Space<T>, RingOperations<T> {
     /**
      * neutral operation for multiplication
      */
     public val one: T
-
-    public override fun number(value: Number): T = one * value.toDouble()
-
-    /**
-     * Addition of element and scalar.
-     *
-     * @receiver the addend.
-     * @param b the augend.
-     */
-    public operator fun T.plus(b: Number): T = this + number(b)
-
-    /**
-     * Addition of scalar and element.
-     *
-     * @receiver the addend.
-     * @param b the augend.
-     */
-    public operator fun Number.plus(b: T): T = b + this
-
-    /**
-     * Subtraction of element from number.
-     *
-     * @receiver the minuend.
-     * @param b the subtrahend.
-     * @receiver the difference.
-     */
-    public operator fun T.minus(b: Number): T = this - number(b)
-
-    /**
-     * Subtraction of number from element.
-     *
-     * @receiver the minuend.
-     * @param b the subtrahend.
-     * @receiver the difference.
-     */
-    public operator fun Number.minus(b: T): T = -b + this
 }
 
 /**
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/BigInt.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/BigInt.kt
index 20f289596..0be72e80c 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/BigInt.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/BigInt.kt
@@ -1,5 +1,6 @@
 package kscience.kmath.operations
 
+import kscience.kmath.misc.UnstableKMathAPI
 import kscience.kmath.operations.BigInt.Companion.BASE
 import kscience.kmath.operations.BigInt.Companion.BASE_SIZE
 import kscience.kmath.structures.*
@@ -16,7 +17,8 @@ public typealias TBase = ULong
  *
  * @author Robert Drynkin (https://github.com/robdrynkin) and Peter Klimai (https://github.com/pklimai)
  */
-public object BigIntField : Field<BigInt> {
+@OptIn(UnstableKMathAPI::class)
+public object BigIntField : Field<BigInt>, RingWithNumbers<BigInt> {
     override val zero: BigInt = BigInt.ZERO
     override val one: BigInt = BigInt.ONE
 
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Complex.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Complex.kt
index 703931c7c..5695e6696 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Complex.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/Complex.kt
@@ -41,7 +41,7 @@ private val PI_DIV_2 = Complex(PI / 2, 0)
 /**
  * A field of [Complex].
  */
-public object ComplexField : ExtendedField<Complex>, Norm<Complex, Complex> {
+public object ComplexField : ExtendedField<Complex>, Norm<Complex, Complex>, RingWithNumbers<Complex> {
     override val zero: Complex = 0.0.toComplex()
     override val one: Complex = 1.0.toComplex()
 
@@ -156,7 +156,7 @@ public object ComplexField : ExtendedField<Complex>, Norm<Complex, Complex> {
 
     override fun norm(arg: Complex): Complex = sqrt(arg.conjugate * arg)
 
-    override fun symbol(value: String): Complex = if (value == "i") i else super.symbol(value)
+    override fun symbol(value: String): Complex = if (value == "i") i else super<ExtendedField>.symbol(value)
 }
 
 /**
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/NumericAlgebra.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/NumericAlgebra.kt
new file mode 100644
index 000000000..26f93fae8
--- /dev/null
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/NumericAlgebra.kt
@@ -0,0 +1,125 @@
+package kscience.kmath.operations
+
+import kscience.kmath.misc.UnstableKMathAPI
+
+/**
+ * An algebraic structure where elements can have numeric representation.
+ *
+ * @param T the type of element of this structure.
+ */
+public interface NumericAlgebra<T> : Algebra<T> {
+    /**
+     * Wraps a number to [T] object.
+     *
+     * @param value the number to wrap.
+     * @return an object.
+     */
+    public fun number(value: Number): T
+
+    /**
+     * Dynamically dispatches a binary operation with the certain name with numeric first argument.
+     *
+     * This function must follow two properties:
+     *
+     * 1. In case if operation is not defined in the structure, the function throws [kotlin.IllegalStateException].
+     * 2. This function is symmetric with the other [leftSideNumberOperation] overload:
+     * i.e. `leftSideNumberOperationFunction(a)(b, c) == leftSideNumberOperation(a, b)`.
+     *
+     * @param operation the name of operation.
+     * @return an operation.
+     */
+    public fun leftSideNumberOperationFunction(operation: String): (left: Number, right: T) -> T =
+        { l, r -> binaryOperationFunction(operation)(number(l), r) }
+
+    /**
+     * Dynamically invokes a binary operation with the certain name with numeric first argument.
+     *
+     * This function must follow two properties:
+     *
+     * 1. In case if operation is not defined in the structure, the function throws [kotlin.IllegalStateException].
+     * 2. This function is symmetric with second [leftSideNumberOperation] overload:
+     * i.e. `leftSideNumberOperationFunction(a)(b, c) == leftSideNumberOperation(a, b, c)`.
+     *
+     * @param operation the name of operation.
+     * @param left the first argument of operation.
+     * @param right the second argument of operation.
+     * @return a result of operation.
+     */
+    public fun leftSideNumberOperation(operation: String, left: Number, right: T): T =
+        leftSideNumberOperationFunction(operation)(left, right)
+
+    /**
+     * Dynamically dispatches a binary operation with the certain name with numeric first argument.
+     *
+     * This function must follow two properties:
+     *
+     * 1. In case if operation is not defined in the structure, the function throws [kotlin.IllegalStateException].
+     * 2. This function is symmetric with the other [rightSideNumberOperationFunction] overload:
+     * i.e. `rightSideNumberOperationFunction(a)(b, c) == leftSideNumberOperation(a, b, c)`.
+     *
+     * @param operation the name of operation.
+     * @return an operation.
+     */
+    public fun rightSideNumberOperationFunction(operation: String): (left: T, right: Number) -> T =
+        { l, r -> binaryOperationFunction(operation)(l, number(r)) }
+
+    /**
+     * Dynamically invokes a binary operation with the certain name with numeric second argument.
+     *
+     * This function must follow two properties:
+     *
+     * 1. In case if operation is not defined in the structure, the function throws [kotlin.IllegalStateException].
+     * 2. This function is symmetric with the other [rightSideNumberOperationFunction] overload:
+     * i.e. `rightSideNumberOperationFunction(a)(b, c) == rightSideNumberOperation(a, b, c)`.
+     *
+     * @param operation the name of operation.
+     * @param left the first argument of operation.
+     * @param right the second argument of operation.
+     * @return a result of operation.
+     */
+    public fun rightSideNumberOperation(operation: String, left: T, right: Number): T =
+        rightSideNumberOperationFunction(operation)(left, right)
+}
+
+/**
+ * A combination of [NumericAlgebra] and [Ring] that adds intrinsic simple operations on numbers like `T+1`
+ * TODO to be removed and replaced by extensions after multiple receivers are there
+ */
+@UnstableKMathAPI
+public interface RingWithNumbers<T>: Ring<T>, NumericAlgebra<T>{
+    public override fun number(value: Number): T = one * value
+
+    /**
+     * Addition of element and scalar.
+     *
+     * @receiver the addend.
+     * @param b the augend.
+     */
+    public operator fun T.plus(b: Number): T = this + number(b)
+
+    /**
+     * Addition of scalar and element.
+     *
+     * @receiver the addend.
+     * @param b the augend.
+     */
+    public operator fun Number.plus(b: T): T = b + this
+
+    /**
+     * Subtraction of element from number.
+     *
+     * @receiver the minuend.
+     * @param b the subtrahend.
+     * @receiver the difference.
+     */
+    public operator fun T.minus(b: Number): T = this - number(b)
+
+    /**
+     * Subtraction of number from element.
+     *
+     * @receiver the minuend.
+     * @param b the subtrahend.
+     * @receiver the difference.
+     */
+    public operator fun Number.minus(b: T): T = -b + this
+}
\ No newline at end of file
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/NumberAlgebra.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/numbers.kt
similarity index 97%
rename from kmath-core/src/commonMain/kotlin/kscience/kmath/operations/NumberAlgebra.kt
rename to kmath-core/src/commonMain/kotlin/kscience/kmath/operations/numbers.kt
index a7b73d5e0..de3818aa6 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/NumberAlgebra.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/operations/numbers.kt
@@ -37,7 +37,7 @@ public interface ExtendedFieldOperations<T> :
 /**
  * Advanced Number-like field that implements basic operations.
  */
-public interface ExtendedField<T> : ExtendedFieldOperations<T>, Field<T> {
+public interface ExtendedField<T> : ExtendedFieldOperations<T>, Field<T>, NumericAlgebra<T> {
     public override fun sinh(arg: T): T = (exp(arg) - exp(-arg)) / 2
     public override fun cosh(arg: T): T = (exp(arg) + exp(-arg)) / 2
     public override fun tanh(arg: T): T = (exp(arg) - exp(-arg)) / (exp(-arg) + exp(arg))
@@ -80,6 +80,8 @@ public object RealField : ExtendedField<Double>, Norm<Double, Double> {
     public override val one: Double
         get() = 1.0
 
+    override fun number(value: Number): Double = value.toDouble()
+
     public override fun binaryOperationFunction(operation: String): (left: Double, right: Double) -> Double =
         when (operation) {
             PowerOperations.POW_OPERATION -> ::power
@@ -131,10 +133,13 @@ public object FloatField : ExtendedField<Float>, Norm<Float, Float> {
     public override val one: Float
         get() = 1.0f
 
-    public override fun binaryOperationFunction(operation: String): (left: Float, right: Float) -> Float = when (operation) {
-        PowerOperations.POW_OPERATION -> ::power
-        else -> super.binaryOperationFunction(operation)
-    }
+    override fun number(value: Number): Float = value.toFloat()
+
+    public override fun binaryOperationFunction(operation: String): (left: Float, right: Float) -> Float =
+        when (operation) {
+            PowerOperations.POW_OPERATION -> ::power
+            else -> super.binaryOperationFunction(operation)
+        }
 
     public override inline fun add(a: Float, b: Float): Float = a + b
     public override inline fun multiply(a: Float, k: Number): Float = a * k.toFloat()
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/ComplexNDField.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/ComplexNDField.kt
index f1f1074e5..6de69cabe 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/ComplexNDField.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/ComplexNDField.kt
@@ -1,9 +1,7 @@
 package kscience.kmath.structures
 
-import kscience.kmath.operations.Complex
-import kscience.kmath.operations.ComplexField
-import kscience.kmath.operations.FieldElement
-import kscience.kmath.operations.complex
+import kscience.kmath.misc.UnstableKMathAPI
+import kscience.kmath.operations.*
 import kotlin.contracts.InvocationKind
 import kotlin.contracts.contract
 
@@ -12,15 +10,22 @@ public typealias ComplexNDElement = BufferedNDFieldElement<Complex, ComplexField
 /**
  * An optimized nd-field for complex numbers
  */
+@OptIn(UnstableKMathAPI::class)
 public class ComplexNDField(override val shape: IntArray) :
     BufferedNDField<Complex, ComplexField>,
-    ExtendedNDField<Complex, ComplexField, NDBuffer<Complex>> {
+    ExtendedNDField<Complex, ComplexField, NDBuffer<Complex>>,
+    RingWithNumbers<NDBuffer<Complex>>{
 
     override val strides: Strides = DefaultStrides(shape)
     override val elementContext: ComplexField get() = ComplexField
     override val zero: ComplexNDElement by lazy { produce { zero } }
     override val one: ComplexNDElement by lazy { produce { one } }
 
+    override fun number(value: Number): NDBuffer<Complex> {
+        val c = value.toComplex()
+        return produce { c }
+    }
+
     public inline fun buildBuffer(size: Int, crossinline initializer: (Int) -> Complex): Buffer<Complex> =
         Buffer.complex(size) { initializer(it) }
 
@@ -29,7 +34,7 @@ public class ComplexNDField(override val shape: IntArray) :
      */
     override fun map(
         arg: NDBuffer<Complex>,
-        transform: ComplexField.(Complex) -> Complex
+        transform: ComplexField.(Complex) -> Complex,
     ): ComplexNDElement {
         check(arg)
         val array = buildBuffer(arg.strides.linearSize) { offset -> ComplexField.transform(arg.buffer[offset]) }
@@ -43,7 +48,7 @@ public class ComplexNDField(override val shape: IntArray) :
 
     override fun mapIndexed(
         arg: NDBuffer<Complex>,
-        transform: ComplexField.(index: IntArray, Complex) -> Complex
+        transform: ComplexField.(index: IntArray, Complex) -> Complex,
     ): ComplexNDElement {
         check(arg)
 
@@ -60,7 +65,7 @@ public class ComplexNDField(override val shape: IntArray) :
     override fun combine(
         a: NDBuffer<Complex>,
         b: NDBuffer<Complex>,
-        transform: ComplexField.(Complex, Complex) -> Complex
+        transform: ComplexField.(Complex, Complex) -> Complex,
     ): ComplexNDElement {
         check(a, b)
 
@@ -141,7 +146,7 @@ public fun NDField.Companion.complex(vararg shape: Int): ComplexNDField = Comple
 
 public fun NDElement.Companion.complex(
     vararg shape: Int,
-    initializer: ComplexField.(IntArray) -> Complex
+    initializer: ComplexField.(IntArray) -> Complex,
 ): ComplexNDElement = NDField.complex(*shape).produce(initializer)
 
 /**
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/RealBufferField.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/RealBufferField.kt
index f7b2ee31e..3f4d15c4d 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/RealBufferField.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/RealBufferField.kt
@@ -150,6 +150,8 @@ public class RealBufferField(public val size: Int) : ExtendedField<Buffer<Double
     public override val zero: Buffer<Double> by lazy { RealBuffer(size) { 0.0 } }
     public override val one: Buffer<Double> by lazy { RealBuffer(size) { 1.0 } }
 
+    override fun number(value: Number): Buffer<Double> = RealBuffer(size) { value.toDouble() }
+
     public override fun add(a: Buffer<Double>, b: Buffer<Double>): RealBuffer {
         require(a.size == size) { "The buffer size ${a.size} does not match context size $size" }
         return RealBufferFieldOperations.add(a, b)
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/RealNDField.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/RealNDField.kt
index ed28fb9f2..3eb1dc4ca 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/RealNDField.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/structures/RealNDField.kt
@@ -1,13 +1,17 @@
 package kscience.kmath.structures
 
+import kscience.kmath.misc.UnstableKMathAPI
 import kscience.kmath.operations.FieldElement
 import kscience.kmath.operations.RealField
+import kscience.kmath.operations.RingWithNumbers
 
 public typealias RealNDElement = BufferedNDFieldElement<Double, RealField>
 
+@OptIn(UnstableKMathAPI::class)
 public class RealNDField(override val shape: IntArray) :
     BufferedNDField<Double, RealField>,
-    ExtendedNDField<Double, RealField, NDBuffer<Double>> {
+    ExtendedNDField<Double, RealField, NDBuffer<Double>>,
+    RingWithNumbers<NDBuffer<Double>>{
 
     override val strides: Strides = DefaultStrides(shape)
 
@@ -15,7 +19,12 @@ public class RealNDField(override val shape: IntArray) :
     override val zero: RealNDElement by lazy { produce { zero } }
     override val one: RealNDElement by lazy { produce { one } }
 
-    public inline fun buildBuffer(size: Int, crossinline initializer: (Int) -> Double): Buffer<Double> =
+    override fun number(value: Number): NDBuffer<Double> {
+        val d = value.toDouble()
+        return produce { d }
+    }
+
+    private inline fun buildBuffer(size: Int, crossinline initializer: (Int) -> Double): Buffer<Double> =
         RealBuffer(DoubleArray(size) { initializer(it) })
 
     /**
@@ -59,7 +68,8 @@ public class RealNDField(override val shape: IntArray) :
         check(a, b)
         return BufferedNDFieldElement(
             this,
-            buildBuffer(strides.linearSize) { offset -> elementContext.transform(a.buffer[offset], b.buffer[offset]) })
+            buildBuffer(strides.linearSize) { offset -> elementContext.transform(a.buffer[offset], b.buffer[offset]) }
+        )
     }
 
     override fun NDBuffer<Double>.toElement(): FieldElement<NDBuffer<Double>, *, out BufferedNDField<Double, RealField>> =
diff --git a/kmath-core/src/commonTest/kotlin/kscience/kmath/structures/NDFieldTest.kt b/kmath-core/src/commonTest/kotlin/kscience/kmath/structures/NDFieldTest.kt
index b763ec7de..1129a8a36 100644
--- a/kmath-core/src/commonTest/kotlin/kscience/kmath/structures/NDFieldTest.kt
+++ b/kmath-core/src/commonTest/kotlin/kscience/kmath/structures/NDFieldTest.kt
@@ -1,14 +1,13 @@
 package kscience.kmath.structures
 
 import kscience.kmath.operations.internal.FieldVerifier
-import kscience.kmath.operations.invoke
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
 internal class NDFieldTest {
     @Test
     fun verify() {
-        (NDField.real(12, 32)) { FieldVerifier(this, one + 3, one - 23, one * 12, 6.66) }
+        NDField.real(12, 32).run { FieldVerifier(this, one + 3, one - 23, one * 12, 6.66) }
     }
 
     @Test
diff --git a/kmath-core/src/jvmMain/kotlin/kscience/kmath/operations/BigNumbers.kt b/kmath-core/src/jvmMain/kotlin/kscience/kmath/operations/BigNumbers.kt
index 2f0978237..9bd6a9fc4 100644
--- a/kmath-core/src/jvmMain/kotlin/kscience/kmath/operations/BigNumbers.kt
+++ b/kmath-core/src/jvmMain/kotlin/kscience/kmath/operations/BigNumbers.kt
@@ -7,7 +7,7 @@ import java.math.MathContext
 /**
  * A field over [BigInteger].
  */
-public object JBigIntegerField : Field<BigInteger> {
+public object JBigIntegerField : Field<BigInteger>, NumericAlgebra<BigInteger> {
     public override val zero: BigInteger
         get() = BigInteger.ZERO
 
@@ -28,9 +28,9 @@ public object JBigIntegerField : Field<BigInteger> {
  *
  * @property mathContext the [MathContext] to use.
  */
-public abstract class JBigDecimalFieldBase internal constructor(public val mathContext: MathContext = MathContext.DECIMAL64) :
-    Field<BigDecimal>,
-    PowerOperations<BigDecimal> {
+public abstract class JBigDecimalFieldBase internal constructor(
+    private val mathContext: MathContext = MathContext.DECIMAL64,
+) : Field<BigDecimal>, PowerOperations<BigDecimal>, NumericAlgebra<BigDecimal> {
     public override val zero: BigDecimal
         get() = BigDecimal.ZERO
 
diff --git a/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrix.kt b/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrix.kt
index 5b7d0a01b..a7d571b58 100644
--- a/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrix.kt
+++ b/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrix.kt
@@ -12,8 +12,10 @@ import org.ejml.simple.SimpleMatrix
  * @property origin the underlying [SimpleMatrix].
  * @author Iaroslav Postovalov
  */
-public class EjmlMatrix(public val origin: SimpleMatrix, features: Set<MatrixFeature> = emptySet()) :
-    FeaturedMatrix<Double> {
+public class EjmlMatrix(
+    public val origin: SimpleMatrix,
+    features: Set<MatrixFeature> = emptySet()
+) :    FeaturedMatrix<Double> {
     public override val rowNum: Int
         get() = origin.numRows()
 
@@ -88,11 +90,7 @@ public class EjmlMatrix(public val origin: SimpleMatrix, features: Set<MatrixFea
         return NDStructure.equals(this, other as? NDStructure<*> ?: return false)
     }
 
-    public override fun hashCode(): Int {
-        var result = origin.hashCode()
-        result = 31 * result + features.hashCode()
-        return result
-    }
+    public override fun hashCode(): Int = origin.hashCode()
 
-    public override fun toString(): String = "EjmlMatrix(origin=$origin, features=$features)"
+    public override fun toString(): String = "EjmlMatrix($origin)"
 }
diff --git a/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrixContext.kt b/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrixContext.kt
index f8791b72c..c8789a4a7 100644
--- a/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrixContext.kt
+++ b/kmath-ejml/src/main/kotlin/kscience/kmath/ejml/EjmlMatrixContext.kt
@@ -1,7 +1,9 @@
 package kscience.kmath.ejml
 
+import kscience.kmath.linear.InverseMatrixFeature
 import kscience.kmath.linear.MatrixContext
 import kscience.kmath.linear.Point
+import kscience.kmath.linear.getFeature
 import kscience.kmath.structures.Matrix
 import org.ejml.simple.SimpleMatrix
 
@@ -77,3 +79,7 @@ public fun EjmlMatrixContext.solve(a: Matrix<Double>, b: Matrix<Double>): EjmlMa
  */
 public fun EjmlMatrixContext.solve(a: Matrix<Double>, b: Point<Double>): EjmlVector =
     EjmlVector(a.toEjml().origin.solve(b.toEjml().origin))
+
+public fun EjmlMatrix.inverted(): EjmlMatrix = getFeature<InverseMatrixFeature<Double>>()!!.inverse as EjmlMatrix
+
+public fun EjmlMatrixContext.inverse(matrix: Matrix<Double>): Matrix<Double> = matrix.toEjml().inverted()
\ No newline at end of file
diff --git a/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/Nd4jArrayAlgebra.kt b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/Nd4jArrayAlgebra.kt
index a8c874fc3..db2a44861 100644
--- a/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/Nd4jArrayAlgebra.kt
+++ b/kmath-nd4j/src/main/kotlin/kscience.kmath.nd4j/Nd4jArrayAlgebra.kt
@@ -1,5 +1,6 @@
 package kscience.kmath.nd4j
 
+import kscience.kmath.misc.UnstableKMathAPI
 import kscience.kmath.operations.*
 import kscience.kmath.structures.NDAlgebra
 import kscience.kmath.structures.NDField
@@ -35,7 +36,7 @@ public interface Nd4jArrayAlgebra<T, C> : NDAlgebra<T, C, Nd4jArrayStructure<T>>
 
     public override fun mapIndexed(
         arg: Nd4jArrayStructure<T>,
-        transform: C.(index: IntArray, T) -> T
+        transform: C.(index: IntArray, T) -> T,
     ): Nd4jArrayStructure<T> {
         check(arg)
         val new = Nd4j.create(*shape).wrap()
@@ -46,7 +47,7 @@ public interface Nd4jArrayAlgebra<T, C> : NDAlgebra<T, C, Nd4jArrayStructure<T>>
     public override fun combine(
         a: Nd4jArrayStructure<T>,
         b: Nd4jArrayStructure<T>,
-        transform: C.(T, T) -> T
+        transform: C.(T, T) -> T,
     ): Nd4jArrayStructure<T> {
         check(a, b)
         val new = Nd4j.create(*shape).wrap()
@@ -61,8 +62,8 @@ public interface Nd4jArrayAlgebra<T, C> : NDAlgebra<T, C, Nd4jArrayStructure<T>>
  * @param T the type of the element contained in ND structure.
  * @param S the type of space of structure elements.
  */
-public interface Nd4jArraySpace<T, S> : NDSpace<T, S, Nd4jArrayStructure<T>>,
-    Nd4jArrayAlgebra<T, S> where S : Space<T> {
+public interface Nd4jArraySpace<T, S : Space<T>> : NDSpace<T, S, Nd4jArrayStructure<T>>, Nd4jArrayAlgebra<T, S> {
+
     public override val zero: Nd4jArrayStructure<T>
         get() = Nd4j.zeros(*shape).wrap()
 
@@ -103,7 +104,9 @@ public interface Nd4jArraySpace<T, S> : NDSpace<T, S, Nd4jArrayStructure<T>>,
  * @param T the type of the element contained in ND structure.
  * @param R the type of ring of structure elements.
  */
-public interface Nd4jArrayRing<T, R> : NDRing<T, R, Nd4jArrayStructure<T>>, Nd4jArraySpace<T, R> where R : Ring<T> {
+@OptIn(UnstableKMathAPI::class)
+public interface Nd4jArrayRing<T, R : Ring<T>> : NDRing<T, R, Nd4jArrayStructure<T>>, Nd4jArraySpace<T, R> {
+
     public override val one: Nd4jArrayStructure<T>
         get() = Nd4j.ones(*shape).wrap()
 
@@ -111,21 +114,21 @@ public interface Nd4jArrayRing<T, R> : NDRing<T, R, Nd4jArrayStructure<T>>, Nd4j
         check(a, b)
         return a.ndArray.mul(b.ndArray).wrap()
     }
-
-    public override operator fun Nd4jArrayStructure<T>.minus(b: Number): Nd4jArrayStructure<T> {
-        check(this)
-        return ndArray.sub(b).wrap()
-    }
-
-    public override operator fun Nd4jArrayStructure<T>.plus(b: Number): Nd4jArrayStructure<T> {
-        check(this)
-        return ndArray.add(b).wrap()
-    }
-
-    public override operator fun Number.minus(b: Nd4jArrayStructure<T>): Nd4jArrayStructure<T> {
-        check(b)
-        return b.ndArray.rsub(this).wrap()
-    }
+//
+//    public override operator fun Nd4jArrayStructure<T>.minus(b: Number): Nd4jArrayStructure<T> {
+//        check(this)
+//        return ndArray.sub(b).wrap()
+//    }
+//
+//    public override operator fun Nd4jArrayStructure<T>.plus(b: Number): Nd4jArrayStructure<T> {
+//        check(this)
+//        return ndArray.add(b).wrap()
+//    }
+//
+//    public override operator fun Number.minus(b: Nd4jArrayStructure<T>): Nd4jArrayStructure<T> {
+//        check(b)
+//        return b.ndArray.rsub(this).wrap()
+//    }
 
     public companion object {
         private val intNd4jArrayRingCache: ThreadLocal<MutableMap<IntArray, IntNd4jArrayRing>> =
@@ -165,7 +168,8 @@ public interface Nd4jArrayRing<T, R> : NDRing<T, R, Nd4jArrayStructure<T>>, Nd4j
  * @param N the type of ND structure.
  * @param F the type field of structure elements.
  */
-public interface Nd4jArrayField<T, F> : NDField<T, F, Nd4jArrayStructure<T>>, Nd4jArrayRing<T, F> where F : Field<T> {
+public interface Nd4jArrayField<T, F : Field<T>> : NDField<T, F, Nd4jArrayStructure<T>>, Nd4jArrayRing<T, F> {
+
     public override fun divide(a: Nd4jArrayStructure<T>, b: Nd4jArrayStructure<T>): Nd4jArrayStructure<T> {
         check(a, b)
         return a.ndArray.div(b.ndArray).wrap()
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 025e4a3c6..a1ea40148 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -8,8 +8,8 @@ pluginManagement {
         maven("https://dl.bintray.com/kotlin/kotlinx")
     }
 
-    val toolsVersion = "0.7.2-dev-2"
-    val kotlinVersion = "1.4.21"
+    val toolsVersion = "0.7.3-1.4.30-RC"
+    val kotlinVersion = "1.4.30-RC"
 
     plugins {
         id("kotlinx.benchmark") version "0.2.0-dev-20"