diff --git a/core/src/commonMain/kotlin/it/unibo/tuprolog/core/visitors/DefaultTermVisitor.kt b/core/src/commonMain/kotlin/it/unibo/tuprolog/core/visitors/DefaultTermVisitor.kt
index 4af3f1937..7d06fd910 100644
--- a/core/src/commonMain/kotlin/it/unibo/tuprolog/core/visitors/DefaultTermVisitor.kt
+++ b/core/src/commonMain/kotlin/it/unibo/tuprolog/core/visitors/DefaultTermVisitor.kt
@@ -1,8 +1,19 @@
 package it.unibo.tuprolog.core.visitors
 
 import it.unibo.tuprolog.core.Term
+import kotlin.js.JsName
+import kotlin.jvm.JvmStatic
 
 abstract class DefaultTermVisitor<T> : AbstractTermVisitor<T>() {
     override fun <X : Term> join(term: X, f1: (X) -> T, vararg fs: (X) -> T): T =
         sequenceOf(f1, *fs).map { it(term) }.first()
+
+    companion object {
+        @JvmStatic
+        @JsName("of")
+        fun <X> of(defaultValue: (Term) -> X): DefaultTermVisitor<X> =
+            object : DefaultTermVisitor<X>() {
+                override fun defaultValue(term: Term): X = defaultValue(term)
+            }
+    }
 }
diff --git a/core/src/commonMain/kotlin/it/unibo/tuprolog/core/visitors/ExhaustiveTermVisitor.kt b/core/src/commonMain/kotlin/it/unibo/tuprolog/core/visitors/ExhaustiveTermVisitor.kt
index f47139077..9588694b2 100644
--- a/core/src/commonMain/kotlin/it/unibo/tuprolog/core/visitors/ExhaustiveTermVisitor.kt
+++ b/core/src/commonMain/kotlin/it/unibo/tuprolog/core/visitors/ExhaustiveTermVisitor.kt
@@ -1,8 +1,19 @@
 package it.unibo.tuprolog.core.visitors
 
 import it.unibo.tuprolog.core.Term
+import kotlin.js.JsName
+import kotlin.jvm.JvmStatic
 
 abstract class ExhaustiveTermVisitor<T> : AbstractTermVisitor<T>() {
     override fun <X : Term> join(term: X, f1: (X) -> T, vararg fs: (X) -> T): T =
         sequenceOf(f1, *fs).map { it(term) }.last()
+
+    companion object {
+        @JvmStatic
+        @JsName("of")
+        fun <X> of(defaultValue: (Term) -> X): ExhaustiveTermVisitor<X> =
+            object : ExhaustiveTermVisitor<X>() {
+                override fun defaultValue(term: Term): X = defaultValue(term)
+            }
+    }
 }
diff --git a/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/PyUtils.kt b/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/PyUtils.kt
new file mode 100644
index 000000000..b86967f19
--- /dev/null
+++ b/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/PyUtils.kt
@@ -0,0 +1,14 @@
+@file:JvmName("PyUtils")
+
+package it.unibo.tuprolog.utils
+
+import it.unibo.tuprolog.utils.impl.IterableWrapper
+import it.unibo.tuprolog.utils.impl.IteratorWrapper
+import it.unibo.tuprolog.utils.impl.SequenceWrapper
+import kotlin.jvm.JvmName
+
+fun <T> iterator(iterator: Iterator<T>): MutableIterator<T> = IteratorWrapper(iterator)
+
+fun <T> iterable(iterable: Iterable<T>): MutableIterable<T> = IterableWrapper(iterable)
+
+fun <T> iterable(sequence: Sequence<T>): MutableIterable<T> = SequenceWrapper(sequence)
diff --git a/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/IterableWrapper.kt b/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/IterableWrapper.kt
new file mode 100644
index 000000000..68e4bcf89
--- /dev/null
+++ b/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/IterableWrapper.kt
@@ -0,0 +1,5 @@
+package it.unibo.tuprolog.utils.impl
+
+internal class IterableWrapper<T>(private val wrapped: Iterable<T>) : MutableIterable<T> {
+    override fun iterator(): MutableIterator<T> = IteratorWrapper(wrapped.iterator())
+}
diff --git a/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/IteratorWrapper.kt b/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/IteratorWrapper.kt
new file mode 100644
index 000000000..864ff04bd
--- /dev/null
+++ b/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/IteratorWrapper.kt
@@ -0,0 +1,12 @@
+package it.unibo.tuprolog.utils.impl
+
+internal class IteratorWrapper<T>(private val wrapped: Iterator<T>) : MutableIterator<T> {
+    override fun hasNext(): Boolean = wrapped.hasNext()
+
+    override fun next(): T = wrapped.next()
+
+    override fun remove() = when (wrapped) {
+        is MutableIterator<T> -> wrapped.remove()
+        else -> throw UnsupportedOperationException()
+    }
+}
diff --git a/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/SequenceWrapper.kt b/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/SequenceWrapper.kt
new file mode 100644
index 000000000..5b95363e3
--- /dev/null
+++ b/utils/src/jvmMain/kotlin/it/unibo/tuprolog/utils/impl/SequenceWrapper.kt
@@ -0,0 +1,5 @@
+package it.unibo.tuprolog.utils.impl
+
+internal class SequenceWrapper<T>(private val wrapped: Sequence<T>) : MutableIterable<T> {
+    override fun iterator(): MutableIterator<T> = IteratorWrapper(wrapped.iterator())
+}