report _which_ element does not belong to the correct set, at the bottom of the tree anyway

1 files changed, 6 insertions, 2 deletions

diff --git a/src/checker_state.rs b/src/checker_state.rs
index 19a7c51..86f229e 100644
--- a/src/checker_state.rs
+++ b/src/checker_state.rs
@@ -13,8 +13,12 @@ pub enum CheckerError {
     Rebinding(String),
     #[display("The following functionality is unimplemented: {_0}")]
     Unimplemented(String),
-    #[display("Element claimed to belong to {claimed} but actually belongs to {real}")]
-    WrongSetForElement { claimed: Set, real: Set },
+    #[display("Element {value} claimed to belong to {claimed} but actually belongs to {real}")]
+    WrongSetForElement {
+        value: ElementValue,
+        claimed: Set,
+        real: Set,
+    },
     #[display("Element {element} does belong to set {claimed}: {reason}")]
     ElementDoesNotBelong {
         element: Element,