diff --git a/src/runtime/c/pgf/intervalmap.h b/src/runtime/c/pgf/intervalmap.h
index ce8c4cf04..59020fb76 100644
--- a/src/runtime/c/pgf/intervalmap.h
+++ b/src/runtime/c/pgf/intervalmap.h
@@ -66,34 +66,6 @@ class PGF_INTERNAL_DECL interval_map {
         }
     }
 
-    static
-    V *lookup(Node *node, size_t start, size_t end)
-    {
-        if (node == NULL) {
-            return NULL;
-        }
-
-        int cmp;
-        if (start < node->start)
-            cmp = -1;
-        else if (start > node->start)
-            cmp = 1;
-        else if (end < node->end)
-            cmp = -1;
-        else if (end > node->end)
-            cmp = 1;
-        else
-            cmp = 0;
-
-        if (cmp < 0) {
-            return lookup(node->left, start, end);
-        } else if (cmp > 0) {
-            return lookup(node->right, start, end);
-        } else {
-            return &node->value;
-        }
-    }
-
     static size_t size(Node *node)
     {
         if (node == 0)
diff --git a/src/runtime/c/pgf/parser.cxx b/src/runtime/c/pgf/parser.cxx
index 6c2de6cf1..70244f20d 100644
--- a/src/runtime/c/pgf/parser.cxx
+++ b/src/runtime/c/pgf/parser.cxx
@@ -1443,16 +1443,14 @@ void PgfParser::suspend(Cont *cont,Item *item,bool do_predict,size_t n_suspended
                 }
             }
         } else {
+            interval_t lin_idx_i = item->interval(ref<PgfLParam>::from_ptr(&symcat->r));
             State *next = cont->state;
             while (next != NULL) {
                 auto it1 = next->completed.find(cont);
                 if (it1 != next->completed.end()) {
-                    auto *it2 = it1->second.lookup(cont->ccat->value);
-                    if (it2 != NULL) {
-                        interval_t lin_idx_i = item->interval(ref<PgfLParam>::from_ptr(&symcat->r));
-                        auto *it3 = it2->lookup(lin_idx_i);
-                        if (it3 != NULL) {
-                            CCat *arg = *it3;
+                    for (auto it2 : it1->second.overlaps(cont->ccat->value)) {
+                        for (auto it3 : it2.second.overlaps(lin_idx_i)) {
+                            CCat *arg = it3.second;
                             Item *new_item = new (item) Item;
                             combine(next, new_item, arg);
                         }
@@ -1641,16 +1639,14 @@ void PgfParseTableMaker::suspend(Cont *cont,Item *item,bool do_predict,size_t n_
                 }
             }
         } else {
+            interval_t lin_idx_i = item->interval(ref<PgfLParam>::from_ptr(&symcat->r));
             State *next = cont->state;
             while (next != NULL) {
                 auto it1 = next->completed.find(cont);
                 if (it1 != next->completed.end()) {
-                    auto *it2 = it1->second.lookup(cont->ccat->value);
-                    if (it2 != NULL) {
-                        interval_t lin_idx_i = item->interval(ref<PgfLParam>::from_ptr(&symcat->r));
-                        auto *it3 = it2->lookup(lin_idx_i);
-                        if (it3 != NULL) {
-                            CCat *arg = *it3;
+                    for (auto it2 : it1->second.overlaps(cont->ccat->value)) {
+                        for (auto it3 : it2.second.overlaps(lin_idx_i)) {
+                            CCat *arg = it3.second;
                             Item *new_item = new (item) Item;
                             combine(next, new_item, arg);
                         }