diff --git a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/RealTensorAlgebra.kt b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/RealTensorAlgebra.kt
index f234d7d6a..cad01c4d0 100644
--- a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/RealTensorAlgebra.kt
+++ b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/RealTensorAlgebra.kt
@@ -1,6 +1,5 @@
 package space.kscience.kmath.tensors
 
-import space.kscience.kmath.linear.LupDecompositionFeature
 import space.kscience.kmath.nd.MutableNDBuffer
 import space.kscience.kmath.structures.RealBuffer
 import space.kscience.kmath.structures.array
@@ -15,6 +14,9 @@ public class RealTensor(
         TensorStrides(shape),
         RealBuffer(buffer)
     ) {
+    /*
+     * TODO: Andrei remove item()
+     */
     override fun item(): Double {
         check(buffer.size > 0) { "The tensor is empty" }
         return buffer[0]
@@ -24,6 +26,10 @@ public class RealTensor(
 
 public class RealTensorAlgebra : TensorPartialDivisionAlgebra<Double, RealTensor> {
 
+    override fun RealTensor.value(): Double {
+        TODO("Andrei")
+    }
+
     override fun Double.plus(other: RealTensor): RealTensor {
         val n = other.buffer.size
         val arr = other.buffer.array
@@ -34,95 +40,95 @@ public class RealTensorAlgebra : TensorPartialDivisionAlgebra<Double, RealTensor
     }
 
     override fun RealTensor.plus(value: Double): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.plus(other: RealTensor): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.plusAssign(value: Double) {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.plusAssign(other: RealTensor) {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun Double.minus(other: RealTensor): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.minus(value: Double): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.minus(other: RealTensor): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.minusAssign(value: Double) {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.minusAssign(other: RealTensor) {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun Double.times(other: RealTensor): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.times(value: Double): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.times(other: RealTensor): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.timesAssign(value: Double) {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.timesAssign(other: RealTensor) {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.unaryMinus(): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.dot(other: RealTensor): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.dotAssign(other: RealTensor) {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.dotRightAssign(other: RealTensor) {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun diagonalEmbedding(diagonalEntries: RealTensor, offset: Int, dim1: Int, dim2: Int): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.transpose(i: Int, j: Int): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.transposeAssign(i: Int, j: Int) {
-        TODO("Not yet implemented")
+        TODO("Alya")
     }
 
     override fun RealTensor.view(shape: IntArray): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.view_as(other: RealTensor): RealTensor {
-        TODO("Not yet implemented")
+        TODO("Andrei")
     }
 
     override fun RealTensor.abs(): RealTensor {
@@ -174,6 +180,10 @@ public class RealTensorAlgebra : TensorPartialDivisionAlgebra<Double, RealTensor
         TODO("Not yet implemented")
     }
 
+    override fun lu_unpack(A_LU: RealTensor, pivots: RealTensor): Triple<RealTensor, RealTensor, RealTensor> {
+        TODO("Not yet implemented")
+    }
+
     override fun RealTensor.svd(): Triple<RealTensor, RealTensor, RealTensor> {
         /**
          * Main first task for @AlyaNovikova
diff --git a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/TensorAlgebra.kt b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/TensorAlgebra.kt
index 03f6f05c2..b2586e1e9 100644
--- a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/TensorAlgebra.kt
+++ b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/TensorAlgebra.kt
@@ -1,7 +1,9 @@
 package space.kscience.kmath.tensors
 
 // https://proofwiki.org/wiki/Definition:Algebra_over_Ring
-public interface TensorAlgebra<T, TensorType : TensorStructure<T>>{
+public interface TensorAlgebra<T, TensorType : TensorStructure<T>> {
+
+    public fun TensorType.value(): T
 
     public operator fun T.plus(other: TensorType): TensorType
     public operator fun TensorType.plus(value: T): TensorType
@@ -69,6 +71,9 @@ public interface TensorPartialDivisionAlgebra<T, TensorType : TensorStructure<T>
     //https://pytorch.org/docs/stable/generated/torch.lu.html
     public fun TensorType.lu(): Pair<TensorType, TensorType>
 
+    //https://pytorch.org/docs/stable/generated/torch.lu_unpack.html
+    public fun lu_unpack(A_LU: TensorType, pivots: TensorType): Triple<TensorType, TensorType, TensorType>
+
     //https://pytorch.org/docs/stable/generated/torch.svd.html
     public fun TensorType.svd(): Triple<TensorType, TensorType, TensorType>
 
diff --git a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/TensorStructure.kt b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/TensorStructure.kt
index 6d2d855b6..3775ea2e5 100644
--- a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/TensorStructure.kt
+++ b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/TensorStructure.kt
@@ -3,6 +3,10 @@ package space.kscience.kmath.tensors
 import space.kscience.kmath.nd.MutableNDStructure
 
 public interface TensorStructure<T> : MutableNDStructure<T> {
+
+    /*
+    * TODO: Andrei remove item() and value()
+     */
     public fun item(): T
 
     // A tensor can have empty shape, in which case it represents just a value