2 files changed, 9 insertions, 1 deletions
diff --git a/src/math/context.rs b/src/math/context.rs
index cb0bca0..e23b96f 100644
--- a/src/math/context.rs
+++ b/src/math/context.rs
@@ -58,6 +58,14 @@ impl Context {
     pub fn function(&self, name: &str) -> Option<&Arc<dyn Function>> {
         self.funcs.get(name)
     }
+
+    pub fn remove_variable(&mut self, name: &str) {
+        self.vars.remove(name);
+    }
+
+    pub fn remove_function(&mut self, name: &str) {
+        self.funcs.remove(name);
+    }
 }
 
 #[macro_export]
diff --git a/src/math/expression_function.rs b/src/math/expression_function.rs
index b9a480f..9debdc4 100644
--- a/src/math/expression_function.rs
+++ b/src/math/expression_function.rs
@@ -9,7 +9,7 @@ use crate::math::{
     function::{Function, FunctionArgument, EmptyFunction}
 };
 
-#[derive(Default)]
+#[derive(Default, Clone)]
 pub struct ExpressionFunction {
     expr: Expression,
     name: String,