diff --git a/src/poly/commitment.rs b/src/poly/commitment.rs
index 0fbdc14..650b17f 100644
--- a/src/poly/commitment.rs
+++ b/src/poly/commitment.rs
@@ -23,13 +23,14 @@ pub struct OpeningProof<C: CurveAffine> {
     z2: C::Scalar,
 }
 
-/// TODO: documentation
+/// An accumulator instance consisting of an evaluation claim and a proof.
 #[derive(Debug, Clone)]
 pub struct Accumulator<C: CurveAffine> {
-    /// TODO: documentation
+    /// The claimed output of the linear-time polycommit opening protocol
     pub g: C,
 
-    /// TODO: documentation
+    /// A vector of 128-bit challenges sampled by the verifier, to be used in
+    /// computing g.
     pub challenges_sq_packed: Vec<Challenge>,
 }
 
diff --git a/src/poly/commitment/verifier.rs b/src/poly/commitment/verifier.rs
index 7038554..2e937f9 100644
--- a/src/poly/commitment/verifier.rs
+++ b/src/poly/commitment/verifier.rs
@@ -138,7 +138,7 @@ impl<C: CurveAffine> OpeningProof<C> {
         // delta
         msm.add_term(Field::one(), self.delta);
 
-        // z2
+        // - [z2] H
         msm.add_to_h(-self.z2);
 
         let guard = Guard {