diff --git a/kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/NumberedPolynomial.kt b/kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/NumberedPolynomial.kt
index 88349f003..c05bc30ec 100644
--- a/kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/NumberedPolynomial.kt
+++ b/kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/NumberedPolynomial.kt
@@ -246,7 +246,7 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
     override operator fun C.minus(other: NumberedPolynomial<C>): NumberedPolynomial<C> =
         if (this.isZero()) -other
         else with(other.coefficients) {
-            if (isEmpty()) NumberedPolynomial<C>(mapOf(listOf<UInt>() to this@minus))
+            if (isEmpty()) NumberedPolynomial<C>(mapOf(emptyList<UInt>() to this@minus))
             else NumberedPolynomial<C>(
                 toMutableMap()
                     .apply {
@@ -279,7 +279,7 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
     override operator fun NumberedPolynomial<C>.plus(other: C): NumberedPolynomial<C> =
         if (other.isZero()) this
         else with(coefficients) {
-            if (isEmpty()) NumberedPolynomial<C>(mapOf(listOf<UInt>() to other))
+            if (isEmpty()) NumberedPolynomial<C>(mapOf(emptyList<UInt>() to other))
             else NumberedPolynomial<C>(
                 toMutableMap()
                     .apply {
@@ -298,7 +298,7 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
     override operator fun NumberedPolynomial<C>.minus(other: C): NumberedPolynomial<C> =
         if (other.isZero()) this
         else with(coefficients) {
-            if (isEmpty()) NumberedPolynomial<C>(mapOf(listOf<UInt>() to other))
+            if (isEmpty()) NumberedPolynomial<C>(mapOf(emptyList<UInt>() to other))
             else NumberedPolynomial<C>(
                 toMutableMap()
                     .apply {
@@ -416,7 +416,7 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
     override val one: NumberedPolynomial<C> =
         NumberedPolynomial<C>(
             mapOf(
-                listOf<UInt>() to constantOne // 1 * x_1^0 * x_2^0 * ...
+                emptyList<UInt>() to constantOne // 1 * x_1^0 * x_2^0 * ...
             )
         )
 
diff --git a/kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/Polynomial.kt b/kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/Polynomial.kt
index 3f0d073b3..722566f5d 100644
--- a/kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/Polynomial.kt
+++ b/kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/Polynomial.kt
@@ -276,7 +276,7 @@ public open class PolynomialSpace<C, A : Ring<C>>(
     public override operator fun Polynomial<C>.minus(other: C): Polynomial<C> =
         if (other.isZero()) this
         else with(coefficients) {
-            if (isEmpty()) Polynomial(listOf(other))
+            if (isEmpty()) Polynomial(listOf(-other))
             else Polynomial(
                 toMutableList()
                     .apply {
diff --git a/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/functions/PolynomialTest.kt b/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/functions/PolynomialTest.kt
index 9e3dea615..e2970d953 100644
--- a/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/functions/PolynomialTest.kt
+++ b/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/functions/PolynomialTest.kt
@@ -5,16 +5,173 @@
 
 package space.kscience.kmath.functions
 
-import space.kscience.kmath.operations.BigInt
 import space.kscience.kmath.operations.algebra
-import space.kscience.kmath.operations.toBigInt
 import space.kscience.kmath.test.misc.Rational
 import space.kscience.kmath.test.misc.RationalField
-import space.kscience.kmath.test.misc.gcd
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
 class PolynomialTest {
+    @Test
+    fun test_Polynomial_Int_plus() {
+        RationalField.polynomial {
+            assertEquals(
+                Polynomial(Rational(-22, 9), Rational(-8, 9), Rational(-8, 7)),
+                Polynomial(Rational(5, 9), Rational(-8, 9), Rational(-8, 7)) + -3,
+                "test 1"
+            )
+            assertEquals(
+                Polynomial(Rational(0), Rational(0), Rational(0), Rational(0)),
+                Polynomial(Rational(-2), Rational(0), Rational(0), Rational(0)) + 2,
+                "test 2"
+            )
+            assertEquals(
+                Polynomial(),
+                Polynomial(Rational(-2)) + 2,
+                "test 3"
+            )
+            assertEquals(
+                Polynomial(),
+                Polynomial<Rational>() + 0,
+                "test 4"
+            )
+            assertEquals(
+                Polynomial(Rational(-1), Rational(0), Rational(0), Rational(0)),
+                Polynomial(Rational(-2), Rational(0), Rational(0), Rational(0)) + 1,
+                "test 5"
+            )
+            assertEquals(
+                Polynomial(Rational(-1)),
+                Polynomial(Rational(-2)) + 1,
+                "test 6"
+            )
+            assertEquals(
+                Polynomial(Rational(2)),
+                Polynomial<Rational>() + 2,
+                "test 7"
+            )
+        }
+    }
+    @Test
+    fun test_Polynomial_Int_minus() {
+        RationalField.polynomial {
+            assertEquals(
+                Polynomial(Rational(32, 9), Rational(-8, 9), Rational(-8, 7)),
+                Polynomial(Rational(5, 9), Rational(-8, 9), Rational(-8, 7)) - -3,
+                "test 1"
+            )
+            assertEquals(
+                Polynomial(Rational(0), Rational(0), Rational(0), Rational(0)),
+                Polynomial(Rational(2), Rational(0), Rational(0), Rational(0)) - 2,
+                "test 2"
+            )
+            assertEquals(
+                Polynomial(),
+                Polynomial(Rational(2)) - 2,
+                "test 3"
+            )
+            assertEquals(
+                Polynomial(),
+                Polynomial<Rational>() - 0,
+                "test 4"
+            )
+            assertEquals(
+                Polynomial(Rational(1), Rational(0), Rational(0), Rational(0)),
+                Polynomial(Rational(2), Rational(0), Rational(0), Rational(0)) - 1,
+                "test 5"
+            )
+            assertEquals(
+                Polynomial(Rational(1)),
+                Polynomial(Rational(2)) - 1,
+                "test 6"
+            )
+            assertEquals(
+                Polynomial(Rational(-2)),
+                Polynomial<Rational>() - 2,
+                "test 7"
+            )
+        }
+    }
+    @Test
+    fun test_Polynomial_Constant_plus() {
+        RationalField.polynomial {
+            assertEquals(
+                Polynomial(Rational(-22, 9), Rational(-8, 9), Rational(-8, 7)),
+                Polynomial(Rational(5, 9), Rational(-8, 9), Rational(-8, 7)) + Rational(-3),
+                "test 1"
+            )
+            assertEquals(
+                Polynomial(Rational(0), Rational(0), Rational(0), Rational(0)),
+                Polynomial(Rational(-2), Rational(0), Rational(0), Rational(0)) + Rational(2),
+                "test 2"
+            )
+            assertEquals(
+                Polynomial(),
+                Polynomial(Rational(-2)) + Rational(2),
+                "test 3"
+            )
+            assertEquals(
+                Polynomial(),
+                Polynomial<Rational>() + Rational(0),
+                "test 4"
+            )
+            assertEquals(
+                Polynomial(Rational(-1), Rational(0), Rational(0), Rational(0)),
+                Polynomial(Rational(-2), Rational(0), Rational(0), Rational(0)) + Rational(1),
+                "test 5"
+            )
+            assertEquals(
+                Polynomial(Rational(-1)),
+                Polynomial(Rational(-2)) + Rational(1),
+                "test 6"
+            )
+            assertEquals(
+                Polynomial(Rational(2)),
+                Polynomial<Rational>() + Rational(2),
+                "test 7"
+            )
+        }
+    }
+    @Test
+    fun test_Polynomial_Constant_minus() {
+        RationalField.polynomial {
+            assertEquals(
+                Polynomial(Rational(32, 9), Rational(-8, 9), Rational(-8, 7)),
+                Polynomial(Rational(5, 9), Rational(-8, 9), Rational(-8, 7)) - Rational(-3),
+                "test 1"
+            )
+            assertEquals(
+                Polynomial(Rational(0), Rational(0), Rational(0), Rational(0)),
+                Polynomial(Rational(2), Rational(0), Rational(0), Rational(0)) - Rational(2),
+                "test 2"
+            )
+            assertEquals(
+                Polynomial(),
+                Polynomial(Rational(2)) - Rational(2),
+                "test 3"
+            )
+            assertEquals(
+                Polynomial(),
+                Polynomial<Rational>() - Rational(0),
+                "test 4"
+            )
+            assertEquals(
+                Polynomial(Rational(1), Rational(0), Rational(0), Rational(0)),
+                Polynomial(Rational(2), Rational(0), Rational(0), Rational(0)) - Rational(1),
+                "test 5"
+            )
+            assertEquals(
+                Polynomial(Rational(1)),
+                Polynomial(Rational(2)) - Rational(1),
+                "test 6"
+            )
+            assertEquals(
+                Polynomial(Rational(-2)),
+                Polynomial<Rational>() - Rational(2),
+                "test 7"
+            )
+        }
+    }
     @Test
     fun test_Polynomial_Polynomial_plus() {
         RationalField.polynomial {
@@ -48,35 +205,39 @@ class PolynomialTest {
             )
         }
     }
-//    @Test
-//    fun test_Polynomial_Polynomial_minus() {
-//        RationalField.polynomial {
-//            assertEquals(
-//                Polynomial(Rational(1, 2), Rational(3, 5), Rational(-2)) +
-//                        Polynomial(Rational(3), Rational(7, 8), Rational(1, 9)),
-//                Polynomial(Rational(7, 2), Rational(59, 40), Rational(-17, 9)),
-//                "test 1"
-//            )
-//            assertEquals(
-//                Polynomial(Rational(1, 2), Rational(3, 5)) +
-//                        Polynomial(Rational(3), Rational(7, 8), Rational(1, 9)),
-//                Polynomial(Rational(7, 2), Rational(59, 40), Rational(1, 9)),
-//                "test 2"
-//            )
-//            assertEquals(
-//                Polynomial(Rational(1, 2), Rational(3, 5), Rational(0), Rational(0)) +
-//                        Polynomial(Rational(3), Rational(7, 8), Rational(1, 9)),
-//                Polynomial(Rational(7, 2), Rational(59, 40), Rational(1, 9)),
-//                "test 3"
-//            )
-//            assertEquals(
-//                Polynomial(Rational(1, 2), Rational(-3, 5), Rational(7, 3)) +
-//                        Polynomial(Rational(3), Rational(3, 5), Rational(-7, 3)),
-//                Polynomial(Rational(7, 2)),
-//                "test 4"
-//            )
-//        }
-//    }
+    @Test
+    fun test_Polynomial_Polynomial_minus() {
+        RationalField.polynomial {
+            // (5/9 - 8/9 x - 8/7 x^2) - (-5/7 + 5/1 x + 5/8 x^2) ?= 80/63 - 53/9 x - 99/56 x^2
+            assertEquals(
+                Polynomial(Rational(80, 63), Rational(-53, 9), Rational(-99, 56)),
+                Polynomial(Rational(5, 9), Rational(-8, 9), Rational(-8, 7)) -
+                        Polynomial(Rational(-5, 7), Rational(5, 1), Rational(5, 8)),
+                "test 1"
+            )
+            // (-2/9 - 8/3 x) - (0 + 9/4 x + 2/4 x^2) ?= -2/9 - 59/12 x - 2/4 x^2
+            assertEquals(
+                Polynomial(Rational(-2, 9), Rational(-59, 12), Rational(-2, 4)),
+                Polynomial(Rational(-2, 9), Rational(-8, 3)) -
+                        Polynomial(Rational(0), Rational(9, 4), Rational(2, 4)),
+                "test 2"
+            )
+            // (-4/7 - 2/6 x + 0 x^2 + 0 x^3) - (-6/3 - 7/2 x + 2/3 x^2) ?= 10/7 + 19/6 x - 2/3 x^2
+            assertEquals(
+                Polynomial(Rational(10, 7), Rational(19, 6), Rational(-2, 3)),
+                Polynomial(Rational(-4, 7), Rational(-2, 6), Rational(0), Rational(0)) -
+                        Polynomial(Rational(-6, 3), Rational(-7, 2), Rational(2, 3)),
+                "test 3"
+            )
+            // (-2/4 - 6/9 x - 4/9 x^2) - (-2/4 - 6/9 x - 4/9 x^2) ?= 0
+            assertEquals(
+                Polynomial(),
+                Polynomial(Rational(-2, 4), Rational(-6, 9), Rational(-4, 9)) -
+                        Polynomial(Rational(-2, 4), Rational(-6, 9), Rational(-4, 9)),
+                "test 4"
+            )
+        }
+    }
     @Test
     fun simple_polynomial_test() {
         val polynomial : Polynomial<Double>
diff --git a/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/Rational.kt b/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/Rational.kt
index fad13f88a..842e354db 100644
--- a/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/Rational.kt
+++ b/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/Rational.kt
@@ -6,54 +6,23 @@
 package space.kscience.kmath.test.misc
 
 import space.kscience.kmath.misc.UnstableKMathAPI
-import space.kscience.kmath.operations.BigInt
 import space.kscience.kmath.operations.Field
 import space.kscience.kmath.operations.NumbersAddOps
-import space.kscience.kmath.operations.toBigInt
-import space.kscience.kmath.operations.BigInt.Companion.ZERO as I0
-import space.kscience.kmath.operations.BigInt.Companion.ONE as I1
 
-/**
- * The class represents rational numbers.
- *
- * Instances contain [numerator] and [denominator] represented as [Long].
- *
- * Also [numerator] and [denominator] are coprime and [denominator] is positive.
- *
- * @author [Gleb Minaev](https://github.com/lounres)
- */
-public class Rational: Comparable<Rational> {
-    public companion object {
-        /**
-         * Constant containing the zero (the additive identity) of the [Rational] field.
-         */
-        public val ZERO: Rational = Rational(I0)
-        /**
-         * Constant containing the one (the multiplicative identity) of the [Rational] field.
-         */
-        public val ONE: Rational = Rational(I1)
+class Rational {
+    companion object {
+        val ZERO: Rational = Rational(0L)
+        val ONE: Rational = Rational(1L)
     }
 
-    /**
-     * Numerator of the fraction. It's stored as non-negative coprime with [denominator] integer.
-     */
-    public val numerator: BigInt
-    /**
-     * Denominator of the fraction. It's stored as non-zero coprime with [numerator] integer.
-     */
-    public val denominator: BigInt
+    val numerator: Long
+    val denominator: Long
 
-    /**
-     * If [toCheckInput] is `true` before assigning values to [Rational.numerator] and [Rational.denominator] makes them coprime and makes
-     * denominator positive. Otherwise, just assigns the values.
-     *
-     * @throws ArithmeticException If denominator is zero.
-     */
-    internal constructor(numerator: BigInt, denominator: BigInt, toCheckInput: Boolean = true) {
+    internal constructor(numerator: Long, denominator: Long, toCheckInput: Boolean = true) {
         if (toCheckInput) {
-            if (denominator == I0) throw ArithmeticException("/ by zero")
+            if (denominator == 0L) throw ArithmeticException("/ by zero")
 
-            val greatestCommonDivider = gcd(numerator, denominator).let { if (denominator < I0) -it else it }
+            val greatestCommonDivider = gcd(numerator, denominator).let { if (denominator < 0L) -it else it }
 
             this.numerator = numerator / greatestCommonDivider
             this.denominator = denominator / greatestCommonDivider
@@ -63,303 +32,86 @@ public class Rational: Comparable<Rational> {
         }
     }
 
-    /**
-     * Before assigning values to [Rational.numerator] and [Rational.denominator] makes them coprime and makes
-     * denominator positive.
-     *
-     * @throws ArithmeticException If denominator is zero.
-     */
-    public constructor(numerator: BigInt, denominator: BigInt) : this(numerator, denominator, true)
-    public constructor(numerator: Int, denominator: BigInt) : this(numerator.toBigInt(), denominator, true)
-    public constructor(numerator: Long, denominator: BigInt) : this(numerator.toBigInt(), denominator, true)
-    public constructor(numerator: BigInt, denominator: Int) : this(numerator, denominator.toBigInt(), true)
-    public constructor(numerator: BigInt, denominator: Long) : this(numerator, denominator.toBigInt(), true)
-    public constructor(numerator: Int, denominator: Int) : this(numerator.toBigInt(), denominator.toBigInt(), true)
-    public constructor(numerator: Int, denominator: Long) : this(numerator.toBigInt(), denominator.toBigInt(), true)
-    public constructor(numerator: Long, denominator: Int) : this(numerator.toBigInt(), denominator.toBigInt(), true)
-    public constructor(numerator: Long, denominator: Long) : this(numerator.toBigInt(), denominator.toBigInt(), true)
-    public constructor(numerator: BigInt) : this(numerator, I1, false)
-    public constructor(numerator: Int) : this(numerator.toBigInt(), I1, false)
-    public constructor(numerator: Long) : this(numerator.toBigInt(), I1, false)
+    constructor(numerator: Int, denominator: Int) : this(numerator.toLong(), denominator.toLong(), true)
+    constructor(numerator: Int, denominator: Long) : this(numerator.toLong(), denominator, true)
+    constructor(numerator: Long, denominator: Int) : this(numerator, denominator.toLong(), true)
+    constructor(numerator: Long, denominator: Long) : this(numerator, denominator, true)
+    constructor(numerator: Int) : this(numerator.toLong(), 1L, false)
+    constructor(numerator: Long) : this(numerator, 1L, false)
 
-    /**
-     * Returns the same instant.
-     */
-    public operator fun unaryPlus(): Rational = this
-
-    /**
-     * Returns negation of the instant of [Rational] field.
-     */
-    public operator fun unaryMinus(): Rational = Rational(-this.numerator, this.denominator)
-
-    /**
-     * Returns sum of the instants of [Rational] field.
-     */
-    public operator fun plus(other: Rational): Rational =
+    operator fun unaryPlus(): Rational = this
+    operator fun unaryMinus(): Rational = Rational(-this.numerator, this.denominator)
+    operator fun plus(other: Rational): Rational =
         Rational(
             numerator * other.denominator + denominator * other.numerator,
             denominator * other.denominator
         )
-
-    /**
-     * Returns sum of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun plus(other: BigInt): Rational =
+    operator fun plus(other: Int): Rational =
+        Rational(
+            numerator + denominator * other.toLong(),
+            denominator
+        )
+    operator fun plus(other: Long): Rational =
         Rational(
             numerator + denominator * other,
             denominator
         )
-
-    /**
-     * Returns sum of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun plus(other: Int): Rational =
-        Rational(
-            numerator + denominator * other.toBigInt(),
-            denominator
-        )
-
-    /**
-     * Returns sum of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun plus(other: Long): Rational =
-        Rational(
-            numerator + denominator * other.toBigInt(),
-            denominator
-        )
-
-    /**
-     * Returns difference of the instants of [Rational] field.
-     */
-    public operator fun minus(other: Rational): Rational =
+    operator fun minus(other: Rational): Rational =
         Rational(
             numerator * other.denominator - denominator * other.numerator,
             denominator * other.denominator
         )
-
-    /**
-     * Returns difference of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun minus(other: BigInt): Rational =
+    operator fun minus(other: Int): Rational =
+        Rational(
+            numerator - denominator * other.toLong(),
+            denominator
+        )
+    operator fun minus(other: Long): Rational =
         Rational(
             numerator - denominator * other,
             denominator
         )
-
-    /**
-     * Returns difference of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun minus(other: Int): Rational =
-        Rational(
-            numerator - denominator * other.toBigInt(),
-            denominator
-        )
-
-    /**
-     * Returns difference of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun minus(other: Long): Rational =
-        Rational(
-            numerator - denominator * other.toBigInt(),
-            denominator
-        )
-
-    /**
-     * Returns product of the instants of [Rational] field.
-     */
-    public operator fun times(other: Rational): Rational =
+    operator fun times(other: Rational): Rational =
         Rational(
             numerator * other.numerator,
             denominator * other.denominator
         )
-
-    /**
-     * Returns product of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun times(other: BigInt): Rational =
+    operator fun times(other: Int): Rational =
+        Rational(
+            numerator * other.toLong(),
+            denominator
+        )
+    operator fun times(other: Long): Rational =
         Rational(
             numerator * other,
             denominator
         )
-
-    /**
-     * Returns product of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun times(other: Int): Rational =
-        Rational(
-            numerator * other.toBigInt(),
-            denominator
-        )
-
-    /**
-     * Returns product of the instants of [Rational] field. [other] is represented as [Rational].
-     */
-    public operator fun times(other: Long): Rational =
-        Rational(
-            numerator * other.toBigInt(),
-            denominator
-        )
-
-    /**
-     * Returns quotient of the instants of [Rational] field.
-     *
-     * @throws ArithmeticException if [other] is the zero of the field it can't be a divisor.
-     */
-    public operator fun div(other: Rational): Rational =
+    operator fun div(other: Rational): Rational =
         Rational(
             numerator * other.denominator,
             denominator * other.numerator
         )
-
-    /**
-     * Returns quotient of the instants of [Rational] field. [other] is represented as [Rational].
-     *
-     * @throws ArithmeticException if [other] is the zero of the field it can't be a divisor.
-     */
-    public operator fun div(other: BigInt): Rational =
+    operator fun div(other: Int): Rational =
+        Rational(
+            numerator,
+            denominator * other.toLong()
+        )
+    operator fun div(other: Long): Rational =
         Rational(
             numerator,
             denominator * other
         )
-
-    /**
-     * Returns quotient of the instants of [Rational] field. [other] is represented as [Rational].
-     *
-     * @throws ArithmeticException if [other] is the zero of the field it can't be a divisor.
-     */
-    public operator fun div(other: Int): Rational =
-        Rational(
-            numerator,
-            denominator * other.toBigInt()
-        )
-
-    /**
-     * Returns quotient of the instants of [Rational] field. [other] is represented as [Rational].
-     *
-     * @throws ArithmeticException if [other] is the zero of the field it can't be a divisor.
-     */
-    public operator fun div(other: Long): Rational =
-        Rational(
-            numerator,
-            denominator * other.toBigInt()
-        )
-
-    /**
-     * Returns reminder from integral division.
-     *
-     * @throws ArithmeticException if [other] is the zero of the field it can't be a divisor.
-     */
-    public operator fun rem(other: Rational): Rational =
-        Rational(
-            (numerator * other.denominator) % (denominator * other.numerator),
-            denominator * other.denominator
-        )
-
-    /**
-     * Returns reminder from integral division.
-     *
-     * @throws ArithmeticException if [other] is the zero of the field it can't be a divisor.
-     */
-    public operator fun rem(other: BigInt): Rational =
-        Rational(
-            numerator % denominator * other,
-            denominator * other
-        )
-
-    /**
-     * Returns reminder from integral division.
-     *
-     * @throws ArithmeticException if [other] is the zero of the field it can't be a divisor.
-     */
-    public operator fun rem(other: Int): Rational =
-        Rational(
-            numerator % denominator * other.toBigInt(),
-            denominator * other.toBigInt()
-        )
-
-    /**
-     * Returns reminder from integral division.
-     *
-     * @throws ArithmeticException if [other] is the zero of the field it can't be a divisor.
-     */
-    public operator fun rem(other: Long): Rational =
-        Rational(
-            numerator % denominator * other.toBigInt(),
-            denominator * other.toBigInt()
-        )
-
-    /**
-     * Checks equality of the instance to [other].
-     *
-     * [BigInt], [Int] and [Long] values are also checked as Rational ones.
-     */
     override fun equals(other: Any?): Boolean =
         when (other) {
             is Rational -> numerator == other.numerator && denominator == other.denominator
-            is BigInt -> numerator == other && denominator == I1
-            is Int -> numerator == other && denominator == I1
-            is Long -> numerator == other && denominator == I1
+            is Int -> numerator == other && denominator == 1L
+            is Long -> numerator == other && denominator == 1L
             else -> false
         }
 
-    /**
-     * Compares the instance to [other] as [Comparable.compareTo].
-     *
-     * @see Comparable.compareTo
-     */
-    override operator fun compareTo(other: Rational): Int = (numerator * other.denominator).compareTo(other.numerator * denominator)
+    override fun hashCode(): Int = 31 * numerator.hashCode() + denominator.hashCode()
 
-    /**
-     * Compares the instance to [other] as [Comparable.compareTo].
-     *
-     * [Integer] values are also checked as Rational ones.
-     *
-     * @see Comparable.compareTo
-     */
-    public operator fun compareTo(other: BigInt): Int = (numerator).compareTo(denominator * other)
-
-    /**
-     * Compares the instance to [other] as [Comparable.compareTo].
-     *
-     * [Int] values are also checked as Rational ones.
-     *
-     * @see Comparable.compareTo
-     */
-    public operator fun compareTo(other: Int): Int = (numerator).compareTo(denominator * other.toBigInt())
-
-    /**
-     * Compares the instance to [other] as [Comparable.compareTo].
-     *
-     * [Long] values are also checked as Rational ones.
-     *
-     * @see Comparable.compareTo
-     */
-    public operator fun compareTo(other: Long): Int = (numerator).compareTo(denominator * other.toBigInt())
-
-    public override fun hashCode(): Int = 31 * numerator.hashCode() + denominator.hashCode()
-
-//    /** Creates a range from this value to the specified [other] value. */
-//    operator fun rangeTo(other: JBInt) = ClosedRationalRange(this, other.toRational())
-//    /** Creates a range from this value to the specified [other] value. */
-//    operator fun rangeTo(other: Rational) = ClosedRationalRange(this, other)
-//    /** Creates a range from this value to the specified [other] value. */
-//    operator fun rangeTo(other: Int) = ClosedRationalRange(this, other.toRational())
-//    /** Creates a range from this value to the specified [other] value. */
-//    operator fun rangeTo(other: Long) = ClosedRationalRange(this, other.toRational())
-
-    public fun toRational(): Rational = this
-
-    public fun toBigInt(): BigInt = numerator / denominator
-
-//    public fun toInt(): Int = (numerator / denominator).toInt()
-//
-//    public fun toLong(): Long = (numerator / denominator).toLong()
-//
-//    public fun toDouble(): Double = (numerator.toDouble() / denominator.toDouble())
-//
-//    public fun toFloat(): Float = (numerator.toFloat() / denominator.toFloat())
-
-    public override fun toString(): String = if (denominator == I1) "$numerator" else "$numerator/$denominator"
+    override fun toString(): String = if (denominator == 1L) "$numerator" else "$numerator/$denominator"
 }
 
 
@@ -368,7 +120,7 @@ public class Rational: Comparable<Rational> {
  */
 @Suppress("EXTENSION_SHADOWED_BY_MEMBER", "OVERRIDE_BY_INLINE", "NOTHING_TO_INLINE")
 @OptIn(UnstableKMathAPI::class)
-public object RationalField : Field<Rational>, NumbersAddOps<Rational> {
+object RationalField : Field<Rational>, NumbersAddOps<Rational> {
     override inline val zero: Rational get() = Rational.ZERO
     override inline val one: Rational get() = Rational.ONE
 
diff --git a/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/RationalWithMemorization.kt b/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/RationalWithMemorization.kt
index 6aa5ecc09..05d9115fa 100644
--- a/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/RationalWithMemorization.kt
+++ b/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/RationalWithMemorization.kt
@@ -12,7 +12,7 @@ class RationalWithMemorization private constructor(
     val value: Rational,
     override val memory : OperationsMemory
 ): WithMemorization {
-    public companion object {
+    companion object {
         /**
          * Constant containing the zero (the additive identity) of the [Rational] field.
          */
@@ -22,48 +22,42 @@ class RationalWithMemorization private constructor(
          */
         public val ONE: RationalWithMemorization = RationalWithMemorization(Rational.ONE, object : Endpoint {})
     }
-    public constructor(numerator: BigInt, denominator: BigInt) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: Int, denominator: BigInt) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: Long, denominator: BigInt) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: BigInt, denominator: Int) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: BigInt, denominator: Long) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: Int, denominator: Int) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: Int, denominator: Long) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: Long, denominator: Int) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: Long, denominator: Long) : this(Rational(numerator, denominator), object : Endpoint {})
-    public constructor(numerator: BigInt) : this(Rational(numerator), object : Endpoint {})
-    public constructor(numerator: Int) : this(Rational(numerator), object : Endpoint {})
-    public constructor(numerator: Long) : this(Rational(numerator), object : Endpoint {})
+    constructor(numerator: Int, denominator: Int) : this(Rational(numerator, denominator), object : Endpoint {})
+    constructor(numerator: Int, denominator: Long) : this(Rational(numerator, denominator), object : Endpoint {})
+    constructor(numerator: Long, denominator: Int) : this(Rational(numerator, denominator), object : Endpoint {})
+    constructor(numerator: Long, denominator: Long) : this(Rational(numerator, denominator), object : Endpoint {})
+    constructor(numerator: Int) : this(Rational(numerator), object : Endpoint {})
+    constructor(numerator: Long) : this(Rational(numerator), object : Endpoint {})
 
-    public operator fun unaryPlus(): RationalWithMemorization = this
-    public operator fun unaryMinus(): RationalWithMemorization = RationalWithMemorization(
+    operator fun unaryPlus(): RationalWithMemorization = this
+    operator fun unaryMinus(): RationalWithMemorization = RationalWithMemorization(
         -value,
         object : Negation {
             override val negated: OperationsMemory = memory
         }
     )
-    public operator fun plus(other: RationalWithMemorization): RationalWithMemorization = RationalWithMemorization(
+    operator fun plus(other: RationalWithMemorization): RationalWithMemorization = RationalWithMemorization(
         value + other.value,
         object : Sum {
             override val augend: OperationsMemory = memory
             override val addend: OperationsMemory = other.memory
         }
     )
-    public operator fun minus(other: RationalWithMemorization): RationalWithMemorization = RationalWithMemorization(
+    operator fun minus(other: RationalWithMemorization): RationalWithMemorization = RationalWithMemorization(
         value - other.value,
         object : Difference {
             override val minuend: OperationsMemory = memory
             override val subtrahend: OperationsMemory = other.memory
         }
     )
-    public operator fun times(other: RationalWithMemorization): RationalWithMemorization = RationalWithMemorization(
+    operator fun times(other: RationalWithMemorization): RationalWithMemorization = RationalWithMemorization(
         value * other.value,
         object : Product {
             override val multiplicand: OperationsMemory = memory
             override val multiplier: OperationsMemory = other.memory
         }
     )
-    public operator fun div(other: RationalWithMemorization): RationalWithMemorization = RationalWithMemorization(
+    operator fun div(other: RationalWithMemorization): RationalWithMemorization = RationalWithMemorization(
         value / other.value,
         object : Quotient {
             override val dividend: OperationsMemory = memory
@@ -71,16 +65,16 @@ class RationalWithMemorization private constructor(
         }
     )
 
-    public override fun equals(other: Any?): Boolean =
+    override fun equals(other: Any?): Boolean =
         other is RationalWithMemorization && value == other.value
 
-    public override fun hashCode(): Int = value.hashCode()
+    override fun hashCode(): Int = value.hashCode()
 
-    public override fun toString(): String = value.toString()
+    override fun toString(): String = value.toString()
 }
 
 @Suppress("EXTENSION_SHADOWED_BY_MEMBER", "OVERRIDE_BY_INLINE", "NOTHING_TO_INLINE")
-public object RationalWithMemorizationRing : Ring<RationalWithMemorization> {
+object RationalWithMemorizationRing : Ring<RationalWithMemorization> {
     override inline val zero: RationalWithMemorization get() = RationalWithMemorization.ZERO
     override inline val one: RationalWithMemorization get() = RationalWithMemorization.ONE
 
@@ -94,7 +88,7 @@ public object RationalWithMemorizationRing : Ring<RationalWithMemorization> {
 }
 
 @Suppress("EXTENSION_SHADOWED_BY_MEMBER", "OVERRIDE_BY_INLINE", "NOTHING_TO_INLINE")
-public object RationalWithMemorizationField : Field<RationalWithMemorization> {
+object RationalWithMemorizationField : Field<RationalWithMemorization> {
     override inline val zero: RationalWithMemorization get() = RationalWithMemorization.ZERO
     override inline val one: RationalWithMemorization get() = RationalWithMemorization.ONE
 
diff --git a/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/misc.kt b/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/misc.kt
index eab29842c..2eb421024 100644
--- a/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/misc.kt
+++ b/kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/misc.kt
@@ -5,21 +5,8 @@
 
 package space.kscience.kmath.test.misc
 
-import space.kscience.kmath.operations.*
-import space.kscience.kmath.operations.BigInt.Companion.ZERO as I0
+import kotlin.math.abs
 
 // TODO: Move to corresponding module "kmath-number-theory"
 
-/**
- * Computes [Greatest Common Divisor](https://en.wikipedia.org/wiki/Greatest_common_divisor) of [a] and [b].
- *
- * It's computed by [Euclidean algorithm](https://en.wikipedia.org/wiki/Greatest_common_divisor#Euclidean_algorithm).
- * Hence, its time complexity is $$O(\log(a+b))$$ (see [Wolfram MathWorld](https://mathworld.wolfram.com/EuclideanAlgorithm.html)).
- */
-public tailrec fun gcd(a: BigInt, b: BigInt): BigInt = if (a == I0) abs(b) else gcd(b % a, a)
-
-/**
- * Computes [Greatest Common Divisor](https://en.wikipedia.org/wiki/Greatest_common_divisor) of the [values].
- */
-public fun gcd(vararg values: BigInt): BigInt = values.reduce(::gcd)
-public fun gcd(values: Iterable<BigInt>): BigInt = values.reduce(::gcd)
\ No newline at end of file
+tailrec fun gcd(a: Long, b: Long): Long = if (a == 0L) abs(b) else gcd(b % a, a)
\ No newline at end of file