fix parser bug, fix beta reduction for setcoerce, disambiguate set coerce in parser

1 files changed, 6 insertions, 2 deletions

diff --git a/src/checker_signature.rs b/src/checker_signature.rs
index 36b11ca..15203b2 100644
--- a/src/checker_signature.rs
+++ b/src/checker_signature.rs
@@ -58,7 +58,11 @@ impl CheckerState {
                     });
                 };
                 let set = Box::new(self.check_set(*set.clone())?);
-                Ok(Instance::SetCoerce(set))
+                if let Set::ClaimedSet(inner) = *set {
+                    Ok(inner)
+                } else {
+                    Ok(Instance::SetCoerce(set))
+                }
             }
             Instance::Var(ref v) => {
                 // Exactly the same discipline as for Element::Var, see there
@@ -158,7 +162,7 @@ impl CheckerState {
                         Ok(sub_element)
                     }
                     _ => panic!(
-                        "invariant violation: check_element returned neither a record or stuck computation for record set"
+                        "invariant violation: check_instance returned neither a record or stuck computation for record set"
                     ),
                 }
             }