diff --git a/src/research.h b/src/research.h
index 28387bd..98b97ce 100644
--- a/src/research.h
+++ b/src/research.h
@@ -1,7 +1,9 @@
 #ifndef RESEARCH_H
 #define RESEARCH_H
 
-int research (void);		// detect clusters
+bool research (void);		// detect clusters
 int eliminate_c (void);		// eliminate clusters
+int cascade();			// cascade ceiling tiles
+int clear();			// clear matched array;
 
 #endif