diff --git a/src/plugins/e-acsl/share/e-acsl/bittree_model/e_acsl_bittree.h b/src/plugins/e-acsl/share/e-acsl/bittree_model/e_acsl_bittree.h
index 760054a5f81f41fb83b706e126045cbb259c6ea5..9eebfaf1efc3b86358c55b47d57bbf89ea766db6 100644
--- a/src/plugins/e-acsl/share/e-acsl/bittree_model/e_acsl_bittree.h
+++ b/src/plugins/e-acsl/share/e-acsl/bittree_model/e_acsl_bittree.h
@@ -324,7 +324,9 @@ static bt_block * bt_lookup (void * ptr) {
     @*/
   while(!tmp->is_leaf) {
     // if the ptr we are looking for does not share the prefix of tmp
-    if((tmp->addr & tmp->mask) != ((size_t)ptr & tmp->mask)) return NULL;
+    if((tmp->addr & tmp->mask) != ((size_t)ptr & tmp->mask))
+      return NULL;
+
     // two children
     DASSERT(tmp->left != NULL && tmp->right != NULL);
     // the prefix of one child is consistent
@@ -334,10 +336,12 @@ static bt_block * bt_lookup (void * ptr) {
     else if((tmp->left->addr & tmp->left->mask)
 	    == ((size_t)ptr & tmp->left->mask))
       tmp = tmp->left;
-    else return NULL;
+    else
+      return NULL;
   }
 
-  if(tmp->leaf->ptr != (size_t)ptr) return NULL;
+  if(tmp->leaf->ptr != (size_t)ptr)
+    return NULL;
   return tmp->leaf;
 }
 
@@ -346,14 +350,16 @@ static bt_block * bt_lookup (void * ptr) {
    or NULL if such a block does not exist */
 static bt_block * bt_find (void * ptr) {
   bt_node * tmp = bt_root;
-  if(bt_root == NULL || ptr == NULL) return NULL;
+  if(bt_root == NULL || ptr == NULL)
+    return NULL;
 
   bt_node * other_choice = NULL;
 
   while(1) {
     if(tmp->is_leaf) {
       /* tmp cannot contain ptr because its begin addr is higher */
-      if(tmp->addr > (size_t)ptr) return NULL;
+      if(tmp->addr > (size_t)ptr)
+        return NULL;
       /* tmp->addr <= ptr, tmp may contain ptr
        ptr is contained if tmp is large enough (begin addr + size) */
       else if((size_t)ptr < tmp->leaf->size + tmp->addr
diff --git a/src/plugins/e-acsl/share/e-acsl/bittree_model/e_acsl_bittree_api.h b/src/plugins/e-acsl/share/e-acsl/bittree_model/e_acsl_bittree_api.h
index 1f74cf52e0aed16786ac846432189ce47c1c6ea6..6d02033d33fe1f1fb7a97489c7bd70ac050370ac 100644
--- a/src/plugins/e-acsl/share/e-acsl/bittree_model/e_acsl_bittree_api.h
+++ b/src/plugins/e-acsl/share/e-acsl/bittree_model/e_acsl_bittree_api.h
@@ -59,13 +59,15 @@ static void bt_remove(bt_block *b);
 /*! \brief Add a block to the structure */
 static void bt_insert(bt_block *b);
 
-/*! \brief Return block B such that: `\base_addr(B->ptr) == ptr`.
-NB: The function assumes that such a block exists. */
+/*! \brief Look-up a memory block by its base address
+  NB: The function assumes that such a block exists. */
 static bt_block * bt_lookup(void *ptr);
 
-/*! \brief Return block B such that:
-   `\base_addr(B->ptr) <= ptr < (\base_addr(B->ptr) + size)`
-   or NULL if such a block does not exist. */
+/*! \brief Find a memory block containing a given memory address
+ *
+ * Return block B such that:
+ *  `\base_addr(B->ptr) <= ptr < (\base_addr(B->ptr) + size)`
+ *  or NULL if such a block does not exist. */
 static bt_block * bt_find(void *ptr);
 
 /*! \brief Erase the contents of the structure */