From 7904b41e60a5a73104c076487f6d4bc122f4d5fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20L=C3=BChne?= <patrick-github@luehne.de>
Date: Mon, 5 Jun 2017 03:34:13 +0200
Subject: [PATCH] Added unit test covering circular dependencies with #show
 statements.

---
 tests/TestHiddenPredicateElimination.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tests/TestHiddenPredicateElimination.cpp b/tests/TestHiddenPredicateElimination.cpp
index 12d4377..dff0849 100644
--- a/tests/TestHiddenPredicateElimination.cpp
+++ b/tests/TestHiddenPredicateElimination.cpp
@@ -91,4 +91,19 @@ TEST_CASE("[hidden predicate elimination] Hidden predicates are correctly elimin
 			"forall V3 (c(V3) <-> (V3 = 1 or V3 = 2))\n"
 			"forall V4 not d(V4)\n");
 	}
+
+	SECTION("circular dependencies cannot be fully removed")
+	{
+		input <<
+			"a(X) :- b(X).\n"
+			"b(X) :- not c(X).\n"
+			"c(X) :- d(X).\n"
+			"d(X) :- not b(X).\n"
+			"#show a/1.";
+		anthem::translate("input", input, context);
+
+		CHECK(output.str() ==
+			"forall V1 (a(V1) <-> not d(V1))\n"
+			"forall V2 (d(V2) <-> not not d(V2))\n");
+	}
 }