diff --git a/smocore/include/concept.h b/smocore/include/concept.h
index 3cc1c5b..f97c3f7 100644
--- a/smocore/include/concept.h
+++ b/smocore/include/concept.h
@@ -1,11 +1,50 @@
 #ifndef _CONCEPT_H
 #define _CONCEPT_H
 
+#include <vector>
+#include <memory>
+#include <logic.h>
 #include <mentalEntity.h>
 
-class Concept
-: public MentalEntity
+namespace smo {
+namespace concepts {
+
+class Comparator
+:	public MentalEntity, public logic::Operand
 {
+public:
+	/**		EXPLANATION:
+	 * The reference for a Comparator is the fixed mentity or range of mentities
+	 * that this comparator is intended to validate a match against.
+	 *
+	 * There are several mentities against which a comparator can match. At the
+	 * time of writing, we're fairly sure that these will be at minimum,
+	 * qualia, chronomena and mentena.
+	 */
+	std::shared_ptr<MentalEntity> reference;
 };
 
+class ComparatorExpression
+:	public logic::UnaryExpression
+{
+public:
+	ComparatorExpression(
+		logic::Operator &op, std::shared_ptr<Comparator> &comparator
+	)
+	:	logic::UnaryExpression(op, comparator)
+	{}
+};
+
+class CombinatorialLogicExpression
+:	public MentalEntity, public logic::Expression
+{
+public:
+
+};
+
+typedef CombinatorialLogicExpression Concept;
+
+} // namespace concept
+} // namespace smo
+
 #endif
diff --git a/smocore/include/logic.h b/smocore/include/logic.h
new file mode 100644
index 0000000..c52ac91
--- /dev/null
+++ b/smocore/include/logic.h
@@ -0,0 +1,65 @@
+#ifndef _LOGIC_H
+#define _LOGIC_H
+
+#include <memory>
+#include <vector>
+
+namespace smo {
+namespace logic {
+
+class ExpressionPart
+{
+};
+
+class Operator
+:	public ExpressionPart
+{
+};
+
+class OperatorAnd
+: public Operator
+{
+};
+
+class OperatorOr
+: public Operator
+{
+};
+
+class OperatorNot
+: public Operator
+{
+};
+
+class Operand
+:	public ExpressionPart
+{
+};
+
+class UnaryExpression
+:	public ExpressionPart
+{
+public:
+	UnaryExpression(Operator &op, std::shared_ptr<Operand> &operand)
+	:	parts(std::make_pair(op, operand))
+	{}
+public:
+	std::pair<Operator, std::shared_ptr<Operand>> parts;
+};
+
+// Expressions can be chained as parts of a larger expression
+class Expression
+:	public ExpressionPart
+{
+public:
+	// This will eventually take in some data to be evaluated for a match.
+	virtual bool evaluate(void) = 0;
+
+public:
+	std::vector<std::shared_ptr<ExpressionPart>> parts;
+};
+
+} // namespace logic
+} // namespace smo
+
+#endif