diff --git a/src/interpreter/Preprocessor.kt b/src/interpreter/Preprocessor.kt
index c65efd5..97edd8f 100644
--- a/src/interpreter/Preprocessor.kt
+++ b/src/interpreter/Preprocessor.kt
@@ -63,6 +63,8 @@ open class Preprocessor {
                     Functor.of("functor/3") -> FunctorOp(args[0], args[1], args[2])
                     Functor.of("arg/3") -> Arg(args[0], args[1], args[2])
                     Functor.of("clause/2") -> ClauseOp(args[0] as Head, args[1] as Body)
+                    Functor.of("atomic/1") -> AtomicOp(args[0])
+                    Functor.of("compound/1") -> CompoundOp(args[0])
 
                     // Arithmetic
                     Functor.of("inf/0") -> Integer(Int.MAX_VALUE)
@@ -111,7 +113,6 @@ open class Preprocessor {
                     Functor.of("!/0") -> Cut()
                     Functor.of(",/2") -> Conjunction(args[0] as LogicOperand, args[1] as LogicOperand)
                     Functor.of(";/2") -> Disjunction(args[0] as LogicOperand, args[1] as LogicOperand)
-                    Functor.of("|/2") -> Bar(args[0] as LogicOperand, args[1] as LogicOperand)
                     Functor.of("\\+/1") -> Not(args[0] as Goal)
 
                     // Database
diff --git a/src/prolog/builtins/analysisOperators.kt b/src/prolog/builtins/analysisOperators.kt
index 8982313..4aff69e 100644
--- a/src/prolog/builtins/analysisOperators.kt
+++ b/src/prolog/builtins/analysisOperators.kt
@@ -137,3 +137,23 @@ class ClauseOp(private val head: Head, private val body: Body) :
         }
     }
 }
+
+class AtomicOp(private val term: Term) : Operator(Atom("atomic"), null, term) {
+    override fun satisfy(subs: Substitutions): Answers {
+        return if (atomic(term, subs)) {
+            sequenceOf(Result.success(emptyMap()))
+        } else {
+            emptySequence()
+        }
+    }
+}
+
+class CompoundOp(private val term: Term) : Operator(Atom("compound"), null, term) {
+    override fun satisfy(subs: Substitutions): Answers {
+        return if (compound(term, subs)) {
+            sequenceOf(Result.success(emptyMap()))
+        } else {
+            emptySequence()
+        }
+    }
+}