diff --git a/src/lib.rs b/src/lib.rs
index 61f98dd9..dc8693ec 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,6 @@
+//! A free software ISO Prolog system.
 #![recursion_limit = "4112"]
+#![deny(missing_docs)]
 
 #[macro_use]
 extern crate static_assertions;
diff --git a/src/machine/parsed_results.rs b/src/machine/parsed_results.rs
index ec3d4693..4791c777 100644
--- a/src/machine/parsed_results.rs
+++ b/src/machine/parsed_results.rs
@@ -23,10 +23,14 @@ pub enum LeafAnswer {
     /// An exception leaf answer.
     Exception(PrologTerm),
     /// A leaf answer with bindings and residual goals.
-    ///
-    /// Both bindings and residual goals can be empty.
     LeafAnswer {
+        /// The bindings of variables in the query.
+        ///
+        /// Can be empty.
         bindings: BTreeMap<String, PrologTerm>,
+        /// Residual goals.
+        ///
+        /// Can be empty.
         residual_goals: Vec<PrologTerm>,
     },
 }