--- /dev/null
+package org.simantics.scl.runtime.chr;\r
+\r
+public interface Fact {\r
+ /**\r
+ * Activates the fact with the given priority. The method returns\r
+ * the new priority of the fact or a negative number if the fact\r
+ * is deactivated.\r
+ */\r
+ int activate(Object context, int priority);\r
+ boolean isAlive();\r
+}\r