diff --git a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ControllerImpl.kt b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ControllerImpl.kt
index ca394ccb..739fcfbe 100644
--- a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ControllerImpl.kt
+++ b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ControllerImpl.kt
@@ -175,7 +175,7 @@ internal class ControllerImpl (
                         if (status.feedback?.alreadyHandled() == false) {
                             status.feedback.handle(match,
                                                     newParent.match.feedbackKey,
-                                                    processing.principalRuleTags(newParent),
+                                                    processing.basisRuleTags(newParent),
                                                     supervisor)
                         }
                     }
@@ -199,7 +199,7 @@ internal class ControllerImpl (
                     } else if (status.feedback?.alreadyHandled() == false
                         && status.failure.handle(match,
                                                     newParent.match.feedbackKey,
-                                                    processing.principalRuleTags(newParent),
+                                                    processing.basisRuleTags(newParent),
                                                     supervisor)) {
 
                         status.recover()
diff --git a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchJournal.kt b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchJournal.kt
index 471290c4..a4a56223 100644
--- a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchJournal.kt
+++ b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchJournal.kt
@@ -121,7 +121,7 @@ interface MatchJournal :  EvidenceSource {
      */
     fun index(): Index
 
-    fun principalRuleTags(chunk: Chunk): List<Any>
+    fun basisRuleTags(chunk: Chunk): List<Any>
 
     /**
      * Simplifies some search operations on [MatchJournal].
diff --git a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchJournalImpl.kt b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchJournalImpl.kt
index a1f83ba5..8b35e9f4 100644
--- a/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchJournalImpl.kt
+++ b/reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchJournalImpl.kt
@@ -243,12 +243,12 @@ internal open class MatchJournalImpl(
 
     override fun index(): MatchJournal.Index = IndexImpl(hist)
 
-    override fun principalRuleTags(chunk: Chunk): List<Any> {
+    override fun basisRuleTags(chunk: Chunk): List<Any> {
         val ptags = mutableListOf<Any>()
         chunk.justifications().forEach { jn ->
             // hist is sequential, random access can be expensive
             (lookupChunkByEvidence(jn) as? MatchChunk)?.let {
-                if (it.match.isPrincipal) {
+                if (it.match.rule().isBasis) {
                     ptags.add(it.ruleUniqueTag)
                 }
             }
diff --git a/reactor/Core/src/jetbrains/mps/logic/reactor/program/Rule.java b/reactor/Core/src/jetbrains/mps/logic/reactor/program/Rule.java
index 3601fb87..01828281 100644
--- a/reactor/Core/src/jetbrains/mps/logic/reactor/program/Rule.java
+++ b/reactor/Core/src/jetbrains/mps/logic/reactor/program/Rule.java
@@ -40,6 +40,8 @@ public abstract class Rule {
         return Collections.emptyList();
     }
 
+    public boolean isBasis() { return false; }
+
     /**
      * A tag uniquely identifies the rule.
      */