diff --git a/include/plasp/pddl/Expression.h b/include/plasp/pddl/Expression.h
index 49079f1..5da342f 100644
--- a/include/plasp/pddl/Expression.h
+++ b/include/plasp/pddl/Expression.h
@@ -110,7 +110,7 @@ class Expression
 		virtual Type expressionType() const = 0;
 
 		ExpressionPointer normalized();
-		virtual ExpressionPointer simplified();
+		virtual ExpressionPointer reduced();
 		virtual ExpressionPointer negationNormalized();
 		ExpressionPointer negated();
 
diff --git a/include/plasp/pddl/expressions/At.h b/include/plasp/pddl/expressions/At.h
index e76fc91..9113afe 100644
--- a/include/plasp/pddl/expressions/At.h
+++ b/include/plasp/pddl/expressions/At.h
@@ -37,7 +37,7 @@ class At: public ExpressionCRTP<At>
 		void setArgument(ExpressionPointer argument);
 		ExpressionPointer argument() const;
 
-		ExpressionPointer simplified() override;
+		ExpressionPointer reduced() override;
 		ExpressionPointer negationNormalized() override;
 
 		void print(std::ostream &ostream) const override;
diff --git a/include/plasp/pddl/expressions/Binary.h b/include/plasp/pddl/expressions/Binary.h
index e7e3af2..32b2c73 100644
--- a/include/plasp/pddl/expressions/Binary.h
+++ b/include/plasp/pddl/expressions/Binary.h
@@ -31,7 +31,7 @@ class Binary: public ExpressionCRTP<Derived>
 		void setArgument(size_t i, ExpressionPointer argument);
 		const std::array<ExpressionPointer, 2> &arguments() const;
 
-		ExpressionPointer simplified() override;
+		ExpressionPointer reduced() override;
 		ExpressionPointer negationNormalized() override;
 
 		void print(std::ostream &ostream) const override;
@@ -91,13 +91,13 @@ const std::array<ExpressionPointer, 2> &Binary<Derived>::arguments() const
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 template<class Derived>
-inline ExpressionPointer Binary<Derived>::simplified()
+inline ExpressionPointer Binary<Derived>::reduced()
 {
 	for (size_t i = 0; i < m_arguments.size(); i++)
 	{
 		BOOST_ASSERT(m_arguments[i]);
 
-		m_arguments[i] = m_arguments[i]->simplified();
+		m_arguments[i] = m_arguments[i]->reduced();
 	}
 
 	return this;
diff --git a/include/plasp/pddl/expressions/Imply.h b/include/plasp/pddl/expressions/Imply.h
index 61e4ebb..b8c2f1a 100644
--- a/include/plasp/pddl/expressions/Imply.h
+++ b/include/plasp/pddl/expressions/Imply.h
@@ -24,7 +24,7 @@ class Imply: public Binary<Imply>
 		static const std::string Identifier;
 
 	public:
-		ExpressionPointer simplified() override;
+		ExpressionPointer reduced() override;
 };
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/include/plasp/pddl/expressions/NAry.h b/include/plasp/pddl/expressions/NAry.h
index 5d26d98..66760c6 100644
--- a/include/plasp/pddl/expressions/NAry.h
+++ b/include/plasp/pddl/expressions/NAry.h
@@ -33,7 +33,7 @@ class NAry: public ExpressionCRTP<Derived>
 		Expressions &arguments();
 		const Expressions &arguments() const;
 
-		ExpressionPointer simplified() override;
+		ExpressionPointer reduced() override;
 		ExpressionPointer negationNormalized() override;
 
 		void print(std::ostream &ostream) const override;
@@ -121,13 +121,13 @@ Expressions &NAry<Derived>::arguments()
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 template<class Derived>
-inline ExpressionPointer NAry<Derived>::simplified()
+inline ExpressionPointer NAry<Derived>::reduced()
 {
 	for (size_t i = 0; i < m_arguments.size(); i++)
 	{
 		BOOST_ASSERT(m_arguments[i]);
 
-		m_arguments[i] = m_arguments[i]->simplified();
+		m_arguments[i] = m_arguments[i]->reduced();
 	}
 
 	return this;
diff --git a/include/plasp/pddl/expressions/Not.h b/include/plasp/pddl/expressions/Not.h
index 23427c6..dce88ce 100644
--- a/include/plasp/pddl/expressions/Not.h
+++ b/include/plasp/pddl/expressions/Not.h
@@ -32,7 +32,7 @@ class Not: public ExpressionCRTP<Not>
 		void setArgument(ExpressionPointer argument);
 		ExpressionPointer argument() const;
 
-		ExpressionPointer simplified() override;
+		ExpressionPointer reduced() override;
 		ExpressionPointer negationNormalized() override;
 
 		void print(std::ostream &ostream) const override;
diff --git a/src/plasp/pddl/Expression.cpp b/src/plasp/pddl/Expression.cpp
index ac69918..2d2a5e2 100644
--- a/src/plasp/pddl/Expression.cpp
+++ b/src/plasp/pddl/Expression.cpp
@@ -26,12 +26,12 @@ namespace pddl
 
 ExpressionPointer Expression::normalized()
 {
-	return simplified()->negationNormalized();
+	return reduced()->negationNormalized();
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
-ExpressionPointer Expression::simplified()
+ExpressionPointer Expression::reduced()
 {
 	return this;
 }
diff --git a/src/plasp/pddl/expressions/At.cpp b/src/plasp/pddl/expressions/At.cpp
index e4ee339..168d7a8 100644
--- a/src/plasp/pddl/expressions/At.cpp
+++ b/src/plasp/pddl/expressions/At.cpp
@@ -36,9 +36,9 @@ ExpressionPointer At::argument() const
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
-ExpressionPointer At::simplified()
+ExpressionPointer At::reduced()
 {
-	throw utils::TranslatorException("“at” predicates currently not supported");
+	throw utils::TranslatorException("reducing “at” predicates currently not supported");
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/src/plasp/pddl/expressions/Imply.cpp b/src/plasp/pddl/expressions/Imply.cpp
index b99a99c..0e55591 100644
--- a/src/plasp/pddl/expressions/Imply.cpp
+++ b/src/plasp/pddl/expressions/Imply.cpp
@@ -21,13 +21,13 @@ const std::string Imply::Identifier = "imply";
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
-ExpressionPointer Imply::simplified()
+ExpressionPointer Imply::reduced()
 {
 	BOOST_ASSERT(m_arguments[0]);
 	BOOST_ASSERT(m_arguments[1]);
 
-	m_arguments[0] = m_arguments[0]->simplified();
-	m_arguments[1] = m_arguments[1]->simplified();
+	m_arguments[0] = m_arguments[0]->reduced();
+	m_arguments[1] = m_arguments[1]->reduced();
 
 	auto notArgument0 = NotPointer(new Not);
 	notArgument0->setArgument(m_arguments[0]);
@@ -36,7 +36,7 @@ ExpressionPointer Imply::simplified()
 	orExpression->addArgument(notArgument0);
 	orExpression->addArgument(m_arguments[1]);
 
-	return orExpression->simplified();
+	return orExpression;
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/src/plasp/pddl/expressions/Not.cpp b/src/plasp/pddl/expressions/Not.cpp
index 34e85a5..ded0f77 100644
--- a/src/plasp/pddl/expressions/Not.cpp
+++ b/src/plasp/pddl/expressions/Not.cpp
@@ -37,11 +37,11 @@ ExpressionPointer Not::argument() const
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
-ExpressionPointer Not::simplified()
+ExpressionPointer Not::reduced()
 {
 	BOOST_ASSERT(m_argument);
 
-	m_argument = m_argument->simplified();
+	m_argument = m_argument->reduced();
 
 	return this;
 }
diff --git a/tests/TestPDDLNormalization.cpp b/tests/TestPDDLNormalization.cpp
index bf01878..a05c0cc 100644
--- a/tests/TestPDDLNormalization.cpp
+++ b/tests/TestPDDLNormalization.cpp
@@ -10,7 +10,7 @@ using namespace plasp::pddl;
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
-TEST(PDDLNormalizationTests, Simplify)
+TEST(PDDLNormalizationTests, Reduced)
 {
 	auto n1 = expressions::NotPointer(new expressions::Not);
 	auto n2 = expressions::NotPointer(new expressions::Not);
@@ -31,7 +31,7 @@ TEST(PDDLNormalizationTests, Simplify)
 	n1->setArgument(n2);
 
 	std::stringstream output;
-	n1->simplified()->print(output);
+	n1->reduced()->print(output);
 
 	ASSERT_EQ(output.str(), "(not (not (and (or (or (not (a)) (b)) (c)) (d))))");
 }