From c205595ea805c0a921c1d4593d25ca9d1c682c9e Mon Sep 17 00:00:00 2001
From: Bernhard Scholz <Bernhard.Scholz@sydney.edu.au>
Date: Wed, 30 Mar 2022 14:08:19 +1100
Subject: [PATCH 1/4] Fix bug in subsumption for pathological cases

---
 src/ast/transform/MinimiseProgram.cpp | 4 ++++
 src/ram/utility/Utils.h               | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/src/ast/transform/MinimiseProgram.cpp b/src/ast/transform/MinimiseProgram.cpp
index 2b966fb3077..571fa97cf91 100644
--- a/src/ast/transform/MinimiseProgram.cpp
+++ b/src/ast/transform/MinimiseProgram.cpp
@@ -377,6 +377,10 @@ bool MinimiseProgramTransformer::reduceClauseBodies(TranslationUnit& translation
 
     bool changed = false;
     for (auto* clause : program.getClauses()) {
+        if (isA<SubsumptiveClause>(clause)) {
+           break;
+        } 
+
         auto bodyLiterals = clause->getBodyLiterals();
         // TODO: This is n^2. Add AST hashing and use a hash-set.
         std::set<std::size_t> redundantPositions;
diff --git a/src/ram/utility/Utils.h b/src/ram/utility/Utils.h
index cf6c2dfcf27..703171a9800 100644
--- a/src/ram/utility/Utils.h
+++ b/src/ram/utility/Utils.h
@@ -84,6 +84,9 @@ inline Own<Condition> toCondition(const VecOwn<Condition>& conds) {
             result = mk<Conjunction>(std::move(result), clone(cur));
         }
     }
+    if (result == nullptr) {
+        result = mk<True>();
+    }
     return result;
 }
 

From 2671eb220a8221c5d367dcfbc5bfbe339e37c150 Mon Sep 17 00:00:00 2001
From: Bernhard Scholz <Bernhard.Scholz@sydney.edu.au>
Date: Wed, 30 Mar 2022 14:13:07 +1100
Subject: [PATCH 2/4] added test-cases

---
 tests/semantic/subsumption_multiple_rules/mx.csv       |  0
 tests/semantic/subsumption_multiple_rules/nx.csv       |  0
 .../subsumption_multiple_rules.dl                      | 10 ++++++++++
 .../subsumption_multiple_rules.err                     |  3 +++
 4 files changed, 13 insertions(+)
 create mode 100644 tests/semantic/subsumption_multiple_rules/mx.csv
 create mode 100644 tests/semantic/subsumption_multiple_rules/nx.csv

diff --git a/tests/semantic/subsumption_multiple_rules/mx.csv b/tests/semantic/subsumption_multiple_rules/mx.csv
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/semantic/subsumption_multiple_rules/nx.csv b/tests/semantic/subsumption_multiple_rules/nx.csv
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.dl b/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.dl
index 41b1b0bb874..ab6754c2a89 100644
--- a/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.dl
+++ b/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.dl
@@ -103,3 +103,13 @@ ES(_, x1) <= ES(_, x2) :- x1 <= x2.
 AF(b) :- G(g, b), !R(b, d), ES(d, a), ES(d, e).
 .output AF
 
+.decl my(x:number)
+.decl mx(x:number)
+mx(n) <= mx(n) :- my(n). 
+.output mx
+
+.decl nx(x:number)
+nx(n) <= nx(n) :- nx(n). 
+.output nx 
+
+
diff --git a/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.err b/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.err
index 3667c0d222c..843d806dbdb 100644
--- a/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.err
+++ b/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.err
@@ -7,3 +7,6 @@ AF(b) :- G(g, b), !R(b, d), ES(d, a), ES(d, e).
 Warning: Variable e only occurs once in file subsumption_multiple_rules.dl at line 103
 AF(b) :- G(g, b), !R(b, d), ES(d, a), ES(d, e).
 --------------------------------------------^---
+Warning: No rules/facts defined for relation my in file subsumption_multiple_rules.dl at line 106
+.decl my(x:number)
+------^------------

From 8a96e3414c726f456013ccc7cf9a5f84cba24737 Mon Sep 17 00:00:00 2001
From: Bernhard Scholz <Bernhard.Scholz@sydney.edu.au>
Date: Wed, 30 Mar 2022 14:13:38 +1100
Subject: [PATCH 3/4] Reformatting

---
 src/ast/transform/MinimiseProgram.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/ast/transform/MinimiseProgram.cpp b/src/ast/transform/MinimiseProgram.cpp
index 72b6b78a4e5..c56c88de22a 100644
--- a/src/ast/transform/MinimiseProgram.cpp
+++ b/src/ast/transform/MinimiseProgram.cpp
@@ -378,8 +378,8 @@ bool MinimiseProgramTransformer::reduceClauseBodies(TranslationUnit& translation
     bool changed = false;
     for (auto* clause : program.getClauses()) {
         if (isA<SubsumptiveClause>(clause)) {
-           break;
-        } 
+            break;
+        }
 
         auto bodyLiterals = clause->getBodyLiterals();
         // TODO: This is n^2. Add AST hashing and use a hash-set.

From a674fb614fb829c853a00ef9ed2a3655a6c5531d Mon Sep 17 00:00:00 2001
From: Bernhard Scholz <Bernhard.Scholz@sydney.edu.au>
Date: Wed, 30 Mar 2022 14:17:31 +1100
Subject: [PATCH 4/4] Reformatting

---
 .../subsumption_multiple_rules.dl                           | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.dl b/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.dl
index ab6754c2a89..9bcad025595 100644
--- a/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.dl
+++ b/tests/semantic/subsumption_multiple_rules/subsumption_multiple_rules.dl
@@ -105,11 +105,11 @@ AF(b) :- G(g, b), !R(b, d), ES(d, a), ES(d, e).
 
 .decl my(x:number)
 .decl mx(x:number)
-mx(n) <= mx(n) :- my(n). 
+mx(n) <= mx(n) :- my(n).
 .output mx
 
 .decl nx(x:number)
-nx(n) <= nx(n) :- nx(n). 
-.output nx 
+nx(n) <= nx(n) :- nx(n).
+.output nx