diff --git a/include/user/cologex.h b/include/user/cologex.h
index b294a7e..b11114d 100644
--- a/include/user/cologex.h
+++ b/include/user/cologex.h
@@ -5,39 +5,12 @@
 #include <memory>
 #include <mentalEntity.h>
 #include <concept.h>
-#include <user/logic.h>
+#include <user/comparator.h>
 #include <user/stimulusFrame.h>
 
 namespace smo {
 namespace cologex {
 
-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, std::static_pointer_cast<logic::Operand>(comparator))
-	{}
-};
-
 class CombinatorialLogicExpression
 :	public MentalEntity, public logic::Expression, public Concept
 {
diff --git a/include/user/comparator.h b/include/user/comparator.h
new file mode 100644
index 0000000..84222ff
--- /dev/null
+++ b/include/user/comparator.h
@@ -0,0 +1,82 @@
+#ifndef _USER_COMPARATOR_H
+#define _USER_COMPARATOR_H
+
+#include <cstdint>
+#include <memory>
+#include <mentalEntity.h>
+#include <user/logic.h>
+
+namespace smo {
+namespace cologex {
+
+constexpr uint32_t SMO_COMPARATOR_VENDOR_ID = 0x511110FFu;
+constexpr uint32_t SMO_COMPARATOR_TYPE_BODY_SPOT = 0x51100001u;
+constexpr uint32_t SMO_COMPARATOR_TYPE_STIM_FEAT = 0x51100002u;
+constexpr uint32_t SMO_COMPARATOR_TYPE_SIMULTANEITY_STAMP = 0x51100003u;
+
+/** Disk-stable comparator type identity: vendorId + typeId (64 bits packed). */
+struct ComparatorTypeId
+{
+	uint32_t vendorId;
+	uint32_t typeId;
+
+	constexpr uint64_t pack() const
+	{
+		return (static_cast<uint64_t>(vendorId) << 32)
+			| static_cast<uint64_t>(typeId);
+	}
+
+	static constexpr ComparatorTypeId unpack(uint64_t packed)
+	{
+		return ComparatorTypeId{
+			static_cast<uint32_t>(packed >> 32),
+			static_cast<uint32_t>(packed)
+		};
+	}
+
+	constexpr bool operator==(const ComparatorTypeId& other) const
+	{
+		return vendorId == other.vendorId && typeId == other.typeId;
+	}
+
+	constexpr bool operator!=(const ComparatorTypeId& other) const
+	{
+		return !(*this == other);
+	}
+};
+
+class Comparator
+:	public MentalEntity, public logic::Operand
+{
+public:
+	explicit Comparator(MentalEntity::Id id)
+	:	MentalEntity(id)
+	{}
+
+	virtual ~Comparator() = default;
+
+	virtual ComparatorTypeId getTypeId() const = 0;
+
+	/**		EXPLANATION:
+	 * The reference for a Comparator is the fixed mentity or range of mentities
+	 * that this comparator is intended to validate a match against.
+	 */
+	std::shared_ptr<MentalEntity> reference;
+};
+
+class ComparatorExpression
+:	public logic::UnaryExpression
+{
+public:
+	ComparatorExpression(
+		logic::Operator &op, std::shared_ptr<Comparator> &comparator
+	)
+	:	logic::UnaryExpression(
+			op, std::static_pointer_cast<logic::Operand>(comparator))
+	{}
+};
+
+} // namespace cologex
+} // namespace smo
+
+#endif // _USER_COMPARATOR_H