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 cea708342..44a7f20b9 100644
--- a/kmath-ast/src/commonMain/kotlin/kscience/kmath/ast/MstAlgebra.kt
+++ b/kmath-ast/src/commonMain/kotlin/kscience/kmath/ast/MstAlgebra.kt
@@ -7,10 +7,10 @@ import kscience.kmath.operations.*
  */
 public object MstAlgebra : NumericAlgebra<MST> {
     public override fun number(value: Number): MST.Numeric = MST.Numeric(value)
-
     public override fun symbol(value: String): MST.Symbolic = MST.Symbolic(value)
 
-    public override fun unaryOperation(operation: String): (arg: MST) -> MST.Unary = { arg -> MST.Unary(operation, arg) }
+    public override fun unaryOperation(operation: String): (arg: MST) -> MST.Unary =
+        { arg -> MST.Unary(operation, arg) }
 
     public override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST.Binary =
         { left, right -> MST.Binary(operation, left, right) }
@@ -25,92 +25,95 @@ 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)
     override fun add(a: MST, b: MST): MST.Binary = binaryOperation(SpaceOperations.PLUS_OPERATION)(a, b)
-    override fun multiply(a: MST, k: Number): MST = binaryOperation(RingOperations.TIMES_OPERATION)(a, number(k))
+    override fun multiply(a: MST, k: Number): MST.Binary = binaryOperation(RingOperations.TIMES_OPERATION)(a, number(k))
 
-    override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST =
+    override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST.Binary =
         MstAlgebra.binaryOperation(operation)
 
-    override fun unaryOperation(operation: String): (arg: MST) -> MST = MstAlgebra.unaryOperation(operation)
+    override fun unaryOperation(operation: String): (arg: MST) -> MST.Unary = MstAlgebra.unaryOperation(operation)
 }
 
 /**
  * [Ring] over [MST] nodes.
  */
 public object MstRing : Ring<MST>, NumericAlgebra<MST> {
-    override val zero: MST
+    override val zero: MST.Numeric
         get() = MstSpace.zero
-    override val one: MST = number(1.0)
 
-    public override fun number(value: Number): MST = MstSpace.number(value)
-    public override fun symbol(value: String): MST = MstSpace.symbol(value)
-    public override fun add(a: MST, b: MST): MST = MstSpace.add(a, b)
-    public override fun multiply(a: MST, k: Number): MST = MstSpace.multiply(a, k)
-    public override fun multiply(a: MST, b: MST): MST = binaryOperation(RingOperations.TIMES_OPERATION)(a, b)
+    override val one: MST.Numeric by lazy { number(1.0) }
 
-    public override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST =
+    public override fun number(value: Number): MST.Numeric = MstSpace.number(value)
+    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 = binaryOperation(RingOperations.TIMES_OPERATION)(a, b)
+
+    public override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST.Binary =
         MstSpace.binaryOperation(operation)
 
-    public override fun unaryOperation(operation: String): (arg: MST) -> MST = MstAlgebra.unaryOperation(operation)
+    public override fun unaryOperation(operation: String): (arg: MST) -> MST.Unary =
+        MstAlgebra.unaryOperation(operation)
 }
 
 /**
  * [Field] over [MST] nodes.
  */
 public object MstField : Field<MST> {
-    public override val zero: MST
+    public override val zero: MST.Numeric
         get() = MstRing.zero
 
-    public override val one: MST
+    public override val one: MST.Numeric
         get() = MstRing.one
 
-    public override fun symbol(value: String): MST = MstRing.symbol(value)
-    public override fun number(value: Number): MST = MstRing.number(value)
-    public override fun add(a: MST, b: MST): MST = MstRing.add(a, b)
-    public override fun multiply(a: MST, k: Number): MST = MstRing.multiply(a, k)
-    public override fun multiply(a: MST, b: MST): MST = MstRing.multiply(a, b)
-    public override fun divide(a: MST, b: MST): MST = binaryOperation(FieldOperations.DIV_OPERATION)(a, b)
+    public override fun symbol(value: String): MST.Symbolic = MstRing.symbol(value)
+    public override fun number(value: Number): MST.Numeric = MstRing.number(value)
+    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 = binaryOperation(FieldOperations.DIV_OPERATION)(a, b)
 
-    public override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST =
+    public override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST.Binary =
         MstRing.binaryOperation(operation)
 
-    public override fun unaryOperation(operation: String): (arg: MST) -> MST = MstRing.unaryOperation(operation)
+    public override fun unaryOperation(operation: String): (arg: MST) -> MST.Unary = MstRing.unaryOperation(operation)
 }
 
 /**
  * [ExtendedField] over [MST] nodes.
  */
 public object MstExtendedField : ExtendedField<MST> {
-    public override val zero: MST
+    public override val zero: MST.Numeric
         get() = MstField.zero
 
-    public override val one: MST
+    public override val one: MST.Numeric
         get() = MstField.one
 
     public override fun symbol(value: String): MST = MstField.symbol(value)
-    public override fun sin(arg: MST): MST = unaryOperation(TrigonometricOperations.SIN_OPERATION)(arg)
-    public override fun cos(arg: MST): MST = unaryOperation(TrigonometricOperations.COS_OPERATION)(arg)
-    public override fun tan(arg: MST): MST = unaryOperation(TrigonometricOperations.TAN_OPERATION)(arg)
-    public override fun asin(arg: MST): MST = unaryOperation(TrigonometricOperations.ASIN_OPERATION)(arg)
-    public override fun acos(arg: MST): MST = unaryOperation(TrigonometricOperations.ACOS_OPERATION)(arg)
-    public override fun atan(arg: MST): MST = unaryOperation(TrigonometricOperations.ATAN_OPERATION)(arg)
-    public override fun sinh(arg: MST): MST = unaryOperation(HyperbolicOperations.SINH_OPERATION)(arg)
-    public override fun cosh(arg: MST): MST = unaryOperation(HyperbolicOperations.COSH_OPERATION)(arg)
-    public override fun tanh(arg: MST): MST = unaryOperation(HyperbolicOperations.TANH_OPERATION)(arg)
-    public override fun asinh(arg: MST): MST = unaryOperation(HyperbolicOperations.ASINH_OPERATION)(arg)
-    public override fun acosh(arg: MST): MST = unaryOperation(HyperbolicOperations.ACOSH_OPERATION)(arg)
-    public override fun atanh(arg: MST): MST = unaryOperation(HyperbolicOperations.ATANH_OPERATION)(arg)
-    public override fun add(a: MST, b: MST): MST = MstField.add(a, b)
-    public override fun multiply(a: MST, k: Number): MST = MstField.multiply(a, k)
-    public override fun multiply(a: MST, b: MST): MST = MstField.multiply(a, b)
-    public override fun divide(a: MST, b: MST): MST = MstField.divide(a, b)
-    public override fun power(arg: MST, pow: Number): MST = binaryOperation(PowerOperations.POW_OPERATION)(arg, number(pow))
-    public override fun exp(arg: MST): MST = unaryOperation(ExponentialOperations.EXP_OPERATION)(arg)
-    public override fun ln(arg: MST): MST = unaryOperation(ExponentialOperations.LN_OPERATION)(arg)
+    public override fun sin(arg: MST): MST.Unary = unaryOperation(TrigonometricOperations.SIN_OPERATION)(arg)
+    public override fun cos(arg: MST): MST.Unary = unaryOperation(TrigonometricOperations.COS_OPERATION)(arg)
+    public override fun tan(arg: MST): MST.Unary = unaryOperation(TrigonometricOperations.TAN_OPERATION)(arg)
+    public override fun asin(arg: MST): MST.Unary = unaryOperation(TrigonometricOperations.ASIN_OPERATION)(arg)
+    public override fun acos(arg: MST): MST.Unary = unaryOperation(TrigonometricOperations.ACOS_OPERATION)(arg)
+    public override fun atan(arg: MST): MST.Unary = unaryOperation(TrigonometricOperations.ATAN_OPERATION)(arg)
+    public override fun sinh(arg: MST): MST.Unary = unaryOperation(HyperbolicOperations.SINH_OPERATION)(arg)
+    public override fun cosh(arg: MST): MST.Unary = unaryOperation(HyperbolicOperations.COSH_OPERATION)(arg)
+    public override fun tanh(arg: MST): MST.Unary = unaryOperation(HyperbolicOperations.TANH_OPERATION)(arg)
+    public override fun asinh(arg: MST): MST.Unary = unaryOperation(HyperbolicOperations.ASINH_OPERATION)(arg)
+    public override fun acosh(arg: MST): MST.Unary = unaryOperation(HyperbolicOperations.ACOSH_OPERATION)(arg)
+    public override fun atanh(arg: MST): MST.Unary = unaryOperation(HyperbolicOperations.ATANH_OPERATION)(arg)
+    public override fun add(a: MST, b: MST): MST.Binary = MstField.add(a, b)
+    public override fun multiply(a: MST, k: Number): MST.Binary = MstField.multiply(a, k)
+    public override fun multiply(a: MST, b: MST): MST.Binary = MstField.multiply(a, b)
+    public override fun divide(a: MST, b: MST): MST.Binary = MstField.divide(a, b)
 
-    public override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST =
+    public override fun power(arg: MST, pow: Number): MST.Binary =
+        binaryOperation(PowerOperations.POW_OPERATION)(arg, number(pow))
+
+    public override fun exp(arg: MST): MST.Unary = unaryOperation(ExponentialOperations.EXP_OPERATION)(arg)
+    public override fun ln(arg: MST): MST.Unary = unaryOperation(ExponentialOperations.LN_OPERATION)(arg)
+
+    public override fun binaryOperation(operation: String): (left: MST, right: MST) -> MST.Binary =
         MstField.binaryOperation(operation)
 
-    public override fun unaryOperation(operation: String): (arg: MST) -> MST = MstField.unaryOperation(operation)
-    override fun unaryOperation(operation: String, arg: MST): MST.Unary =
-        MST.Unary(operation, arg)
+    public override fun unaryOperation(operation: String): (arg: MST) -> MST.Unary = MstField.unaryOperation(operation)
 }