Clean up

dust-lang/src/abstract_tree/logic.rs

@@ -214,8 +214,8 @@ impl AbstractNode for Logic {
 
                 left_boolean || right_boolean
             }
-            Logic::Not(statement) => {
+            Logic::Not(expression) => {
-                let boolean = run_and_expect_boolean(statement)?;
+                let boolean = run_and_expect_boolean(expression)?;
 
                 !boolean
             }

dust-lang/src/value.rs

@@ -820,6 +820,8 @@ impl Function {
 
         debug!("Calling function");
 
+        self.body
+            .define_and_validate(&self.context, false, SourcePosition(0, usize::MAX))?;
         self.body
             .evaluate(&self.context, false, SourcePosition(0, usize::MAX))
     }

dust-lang/tests/functions.rs

@@ -105,7 +105,7 @@ fn recursion() {
             	}
             }
 
-            fib(4)
+            fib(8)
             "
         ),
         Ok(Some(Value::integer(13)))