message: Remove out-of-place comment
diff: @@ -171,16 +171,6 @@ pub fn symbolic_boolvec<Iptr: SpIndex, I: SpIndex>(
  c_indices.clear();
  c_indices.reserve_exact(a_nnz + b_nnz);
  - // `index` is used as a set to remember which columns of a row of C are
  - // nonzero. At any point in the algorithm, if `index[col] == sentinel0`,
  - // then we know there is no nonzero value in the column. As the algorithm
  - // progresses, we discover nonzero elements. When a nonzero at `col` is
  - // discovered, we store in `index[col]` the column of the preceding
  - // nonzero (storing `sentinel1` for the first nonzero). Therefore,
  - // when we want to collect nonzeros and clear the set, we can simply
  - // follow the trail of column indices, putting back `sentinel0` along
  - // the way. This way, collecting the nonzero indices for a column
  - // has a complexity O(col_nnz).
  let ind_len = a_rows.max(b_rows.max(b_cols));
  assert!(seen.len() == ind_len);
  for elt in seen.iter_mut() {
  