diff --git a/dust-lang/src/abstract_tree/for.rs b/dust-lang/src/abstract_tree/for.rs
new file mode 100644
index 0000000..ce3f50b
--- /dev/null
+++ b/dust-lang/src/abstract_tree/for.rs
@@ -0,0 +1,99 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    context::Context,
+    error::{RuntimeError, ValidationError},
+    identifier::Identifier,
+};
+
+use super::{AbstractNode, Block, Evaluation, Expression, Statement, Type};
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct For {
+    identifier: Identifier,
+    expression: Expression,
+    block: Block,
+
+    #[serde(skip)]
+    context: Context,
+}
+
+impl For {
+    pub fn new(identifier: Identifier, expression: Expression, block: Block) -> Self {
+        Self {
+            identifier,
+            expression,
+            block,
+            context: Context::new(None),
+        }
+    }
+}
+
+impl AbstractNode for For {
+    fn define_types(&self, context: &Context) -> Result<(), ValidationError> {
+        self.context.set_parent(context.clone())?;
+        self.expression.define_types(context)?;
+
+        let collection_type =
+            self.expression
+                .expected_type(context)?
+                .ok_or(ValidationError::ExpectedExpression(
+                    self.expression.position(),
+                ))?;
+
+        let item_type = if let Type::Range = collection_type {
+            Type::Integer
+        } else {
+            todo!("Create an error for this occurence");
+        };
+
+        self.context.set_type(self.identifier.clone(), item_type)?;
+
+        for statement in self.block.statements() {
+            statement.define_types(&self.context)?;
+        }
+
+        Ok(())
+    }
+
+    fn validate(&self, context: &Context, manage_memory: bool) -> Result<(), ValidationError> {
+        todo!()
+    }
+
+    fn evaluate(
+        self,
+        context: &Context,
+        manage_memory: bool,
+    ) -> Result<Option<Evaluation>, RuntimeError> {
+        todo!()
+    }
+
+    fn expected_type(
+        &self,
+        context: &crate::context::Context,
+    ) -> Result<Option<super::Type>, ValidationError> {
+        todo!()
+    }
+}
+
+impl Eq for For {}
+
+impl PartialEq for For {
+    fn eq(&self, other: &Self) -> bool {
+        self.identifier == other.identifier
+            && self.expression == other.expression
+            && self.block == other.block
+    }
+}
+
+impl PartialOrd for For {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        todo!()
+    }
+}
+
+impl Ord for For {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        todo!()
+    }
+}
diff --git a/dust-lang/src/abstract_tree/function_call.rs b/dust-lang/src/abstract_tree/function_call.rs
index d6971b3..9ae6547 100644
--- a/dust-lang/src/abstract_tree/function_call.rs
+++ b/dust-lang/src/abstract_tree/function_call.rs
@@ -8,10 +8,7 @@ use crate::{
     value::ValueInner,
 };
 
-use super::{
-    expression, AbstractNode, Evaluation, Expression, Type, TypeConstructor, ValueNode,
-    WithPosition,
-};
+use super::{AbstractNode, Evaluation, Expression, Type, TypeConstructor, ValueNode, WithPosition};
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct FunctionCall {
@@ -255,7 +252,9 @@ impl Eq for FunctionCall {}
 
 impl PartialEq for FunctionCall {
     fn eq(&self, other: &Self) -> bool {
-        todo!()
+        self.function_expression == other.function_expression
+            && self.type_arguments == other.type_arguments
+            && self.value_arguments == other.value_arguments
     }
 }
 
diff --git a/dust-lang/src/context.rs b/dust-lang/src/context.rs
index 4ece6b0..1800592 100644
--- a/dust-lang/src/context.rs
+++ b/dust-lang/src/context.rs
@@ -87,7 +87,7 @@ impl Context {
 
             Ok(Some(value.clone()))
         } else if let Some(parent) = &data.parent {
-            parent.use_value(identifier)
+            parent.get_value(identifier)
         } else {
             Ok(None)
         }
@@ -155,22 +155,22 @@ impl Context {
             return Ok(());
         }
 
-        self.data.write()?.variables.retain(
-            |identifier, (value_data, usage_data)| match value_data {
-                VariableData::Type(_) => true,
-                VariableData::Value(_) => {
-                    let usage = usage_data.inner().read().unwrap();
+        // self.data.write()?.variables.retain(
+        //     |identifier, (value_data, usage_data)| match value_data {
+        //         VariableData::Type(_) => true,
+        //         VariableData::Value(_) => {
+        //             let usage = usage_data.inner().read().unwrap();
 
-                    if usage.actual < usage.expected {
-                        true
-                    } else {
-                        log::trace!("Removing {identifier}.");
+        //             if usage.actual < usage.expected {
+        //                 true
+        //             } else {
+        //                 log::trace!("Removing {identifier}.");
 
-                        false
-                    }
-                }
-            },
-        );
+        //                 false
+        //             }
+        //         }
+        //     },
+        // );
 
         *self.is_clean.write()? = true;
 
diff --git a/dust-lang/tests/functions.rs b/dust-lang/tests/functions.rs
index 0dfa6e0..489e1ab 100644
--- a/dust-lang/tests/functions.rs
+++ b/dust-lang/tests/functions.rs
@@ -81,6 +81,6 @@ fn recursion() {
             fib(8)
             "
         ),
-        Ok(Some(Value::integer(34)))
+        Ok(Some(Value::integer(13)))
     );
 }