it runs! gets the wrong answer, but runs!

src/syntax/validate.rs

@@ -13,6 +13,7 @@ use std::str::FromStr;
 /// that we're not going to be able to work through. As with most
 /// of these errors, we recommend converting this to a [`Diagnostic`]
 /// and using [`codespan_reporting`] to present them to the user.
+#[derive(Debug)]
 pub enum Error {
     UnboundVariable(Location, String),
     UnknownType(Location, String),
@@ -83,6 +84,9 @@ impl Program {
         let mut warnings = vec![];
 
         for stmt in self.items.iter() {
+            if let TopLevel::Function(Some(name), _, _) = stmt {
+                bound_variables.insert(name.to_string(), name.location.clone());
+            }
             let (mut new_errors, mut new_warnings) = stmt.validate_with_bindings(bound_variables);
             errors.append(&mut new_errors);
             warnings.append(&mut new_warnings);