-/** Returns the pointer associated with pointer key. Hash is
- the hash value computed from key. Returns Null if key not
- in hash table. */
-void *pset_find (pset *, const void *key, unsigned hash);
-void *pset_insert (pset *, const void *key, unsigned hash);
-pset_entry *pset_hinsert (pset *, const void *key, unsigned hash);
-void *pset_remove (pset *, const void *key, unsigned hash);
+/**
+ * Inserts an element pointer into a pset and returns its pset_entry.
+ *
+ * @param pset the pset to insert in
+ * @param key a pointer to the element to be inserted
+ * @param hash the hash-value of the element
+ *
+ * @return a pointer to the pset_entry of the inserted element
+ *
+ * @note
+ * It is not possible to insert on element more than once. If a element
+ * that should be inserted is already in the pset, this functions does
+ * nothing but returning its pset_entry.
+ */
+pset_entry *pset_hinsert (pset *pset, const void *key, unsigned hash);
+
+/**
+ * Removes an element from a pset.
+ *
+ * @param pset the pset to insert in
+ * @param key a pointer to the element to be inserted
+ * @param hash the hash-value of the element
+ *
+ * @return
+ * the pointer to the removed element
+ *
+ * @remark
+ * The current implementation did not allow to remove non-existing elements
+ */
+void *pset_remove (pset *pset, const void *key, unsigned hash);