diff --git a/kmath-core/api/kmath-core.api b/kmath-core/api/kmath-core.api
index ab0555932..92165f795 100644
--- a/kmath-core/api/kmath-core.api
+++ b/kmath-core/api/kmath-core.api
@@ -488,15 +488,9 @@ public final class kscience/kmath/expressions/StringSymbol : kscience/kmath/expr
 }
 
 public abstract interface class kscience/kmath/expressions/Symbol {
-	public static final field Companion Lkscience/kmath/expressions/Symbol$Companion;
 	public abstract fun getIdentity ()Ljava/lang/String;
 }
 
-public final class kscience/kmath/expressions/Symbol$Companion : kotlin/properties/ReadOnlyProperty {
-	public synthetic fun getValue (Ljava/lang/Object;Lkotlin/reflect/KProperty;)Ljava/lang/Object;
-	public fun getValue (Ljava/lang/Object;Lkotlin/reflect/KProperty;)Lkscience/kmath/expressions/Symbol;
-}
-
 public abstract interface class kscience/kmath/expressions/SymbolIndexer {
 	public abstract fun get (Ljava/util/List;Lkscience/kmath/expressions/Symbol;)Ljava/lang/Object;
 	public abstract fun get (Lkscience/kmath/nd/Structure2D;Lkscience/kmath/expressions/Symbol;Lkscience/kmath/expressions/Symbol;)Ljava/lang/Object;
diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/Expression.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/Expression.kt
index 63bbc9312..c53d64871 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/Expression.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/Expression.kt
@@ -3,7 +3,6 @@ package kscience.kmath.expressions
 import kscience.kmath.operations.Algebra
 import kotlin.jvm.JvmName
 import kotlin.properties.ReadOnlyProperty
-import kotlin.reflect.KProperty
 
 /**
  * A marker interface for a symbol. A symbol mus have an identity
@@ -13,13 +12,6 @@ public interface Symbol {
      * Identity object for the symbol. Two symbols with the same identity are considered to be the same symbol.
      */
     public val identity: String
-
-    public companion object : ReadOnlyProperty<Any?, Symbol> {
-        //TODO deprecate and replace by top level function after fix of https://youtrack.jetbrains.com/issue/KT-40121
-        override fun getValue(thisRef: Any?, property: KProperty<*>): Symbol {
-            return StringSymbol(property.name)
-        }
-    }
 }
 
 /**
@@ -103,9 +95,9 @@ public fun <T, E> ExpressionAlgebra<T, E>.bind(symbol: Symbol): E =
 /**
  * A delegate to create a symbol with a string identity in this scope
  */
-public val symbol: ReadOnlyProperty<Any?, Symbol> get() = Symbol
-//TODO does not work directly on native due to https://youtrack.jetbrains.com/issue/KT-40121
-
+public val symbol: ReadOnlyProperty<Any?, Symbol>  = ReadOnlyProperty { thisRef, property ->
+    StringSymbol(property.name)
+}
 
 /**
  * Bind a symbol by name inside the [ExpressionAlgebra]
diff --git a/kmath-for-real/src/commonMain/kotlin/kscience/kmath/real/RealVector.kt b/kmath-for-real/src/commonMain/kotlin/kscience/kmath/real/RealVector.kt
index 596692782..ee2a960a1 100644
--- a/kmath-for-real/src/commonMain/kotlin/kscience/kmath/real/RealVector.kt
+++ b/kmath-for-real/src/commonMain/kotlin/kscience/kmath/real/RealVector.kt
@@ -29,8 +29,10 @@ public inline fun RealVector.map(transform: (Double) -> Double): RealVector =
 public inline fun RealVector.mapIndexed(transform: (index: Int, value: Double) -> Double): RealVector =
     Buffer.real(size) { transform(it, get(it)) }
 
-public operator fun RealVector.plus(other: RealVector): RealVector =
-    mapIndexed { index, value -> value + other[index] }
+public operator fun RealVector.plus(other: RealVector): RealVector {
+    require(size == other.size){"Vector size $size expected but ${other.size} found"}
+    return mapIndexed { index, value -> value + other[index] }
+}
 
 public operator fun RealVector.plus(number: Number): RealVector = map { it + number.toDouble() }
 
@@ -38,22 +40,28 @@ public operator fun Number.plus(vector: RealVector): RealVector = vector + this
 
 public operator fun RealVector.unaryMinus(): Buffer<Double> = map { -it }
 
-public operator fun RealVector.minus(other: RealVector): RealVector =
-    mapIndexed { index, value -> value - other[index] }
+public operator fun RealVector.minus(other: RealVector): RealVector {
+    require(size == other.size){"Vector size $size expected but ${other.size} found"}
+    return mapIndexed { index, value -> value - other[index] }
+}
 
 public operator fun RealVector.minus(number: Number): RealVector = map { it - number.toDouble() }
 
 public operator fun Number.minus(vector: RealVector): RealVector = vector.map { toDouble() - it }
 
-public operator fun RealVector.times(other: RealVector): RealVector =
-    mapIndexed { index, value -> value * other[index] }
+public operator fun RealVector.times(other: RealVector): RealVector {
+    require(size == other.size){"Vector size $size expected but ${other.size} found"}
+    return mapIndexed { index, value -> value * other[index] }
+}
 
 public operator fun RealVector.times(number: Number): RealVector = map { it * number.toDouble() }
 
 public operator fun Number.times(vector: RealVector): RealVector = vector * this
 
-public operator fun RealVector.div(other: RealVector): RealVector =
-    mapIndexed { index, value -> value / other[index] }
+public operator fun RealVector.div(other: RealVector): RealVector {
+    require(size == other.size){"Vector size $size expected but ${other.size} found"}
+    return mapIndexed { index, value -> value / other[index] }
+}
 
 public operator fun RealVector.div(number: Number): RealVector = map { it / number.toDouble() }