diff --git a/gtsam/discrete/DiscreteFactor.h b/gtsam/discrete/DiscreteFactor.h
index 62f1e064b..6fa074379 100644
--- a/gtsam/discrete/DiscreteFactor.h
+++ b/gtsam/discrete/DiscreteFactor.h
@@ -136,6 +136,9 @@ class GTSAM_EXPORT DiscreteFactor : public Factor {
   /**
    * @brief Multiply in a DiscreteFactor and return the result as
    * DiscreteFactor, both via shared pointers.
+   *
+   * @param df DiscreteFactor shared_ptr
+   * @return DiscreteFactor::shared_ptr
    */
   virtual DiscreteFactor::shared_ptr multiply(
       const DiscreteFactor::shared_ptr& df) const = 0;
@@ -167,7 +170,7 @@ class GTSAM_EXPORT DiscreteFactor : public Factor {
    * 
    * @return DiscreteFactor::shared_ptr 
    */
-  virtual DiscreteFactor::shared_ptr scale() const;
+  DiscreteFactor::shared_ptr scale() const;
 
   /**
    * Get the number of non-zero values contained in this factor.
diff --git a/gtsam_unstable/discrete/AllDiff.h b/gtsam_unstable/discrete/AllDiff.h
index 67a6ffd18..1180abad4 100644
--- a/gtsam_unstable/discrete/AllDiff.h
+++ b/gtsam_unstable/discrete/AllDiff.h
@@ -72,11 +72,6 @@ class GTSAM_UNSTABLE_EXPORT AllDiff : public Constraint {
   /// Partially apply known values, domain version
   Constraint::shared_ptr partiallyApply(
       const Domains&) const override;
-
-  // Scale just returns the same constraint.
-  DiscreteFactor::shared_ptr scale() const override {
-    return std::make_shared<AllDiff>(*this);
-  }
 };
 
 }  // namespace gtsam
diff --git a/gtsam_unstable/discrete/BinaryAllDiff.h b/gtsam_unstable/discrete/BinaryAllDiff.h
index 21d5f1642..e96bfdfde 100644
--- a/gtsam_unstable/discrete/BinaryAllDiff.h
+++ b/gtsam_unstable/discrete/BinaryAllDiff.h
@@ -96,11 +96,6 @@ class BinaryAllDiff : public Constraint {
   AlgebraicDecisionTree<Key> errorTree() const override {
     throw std::runtime_error("BinaryAllDiff::error not implemented");
   }
-
-  // Scale just returns the same constraint.
-  DiscreteFactor::shared_ptr scale() const override {
-    return std::make_shared<BinaryAllDiff>(*this);
-  }
 };
 
 }  // namespace gtsam
diff --git a/gtsam_unstable/discrete/Constraint.h b/gtsam_unstable/discrete/Constraint.h
index 91bcdbc20..328fabbea 100644
--- a/gtsam_unstable/discrete/Constraint.h
+++ b/gtsam_unstable/discrete/Constraint.h
@@ -29,9 +29,7 @@ class Domain;
 using Domains = std::map<Key, Domain>;
 
 /**
- * Base class for constraint factors.
- * This class is used to represent constraints on discrete variables.
- * The values are always either 0 or 1, with at least one 1.
+ * Base class for constraint factors
  * Derived classes include SingleValue, BinaryAllDiff, and AllDiff.
  */
 class GTSAM_UNSTABLE_EXPORT Constraint : public DiscreteFactor {
@@ -82,16 +80,6 @@ class GTSAM_UNSTABLE_EXPORT Constraint : public DiscreteFactor {
   /// Partially apply known values, domain version
   virtual shared_ptr partiallyApply(const Domains&) const = 0;
 
-  /// Multiply in a DecisionTreeFactor.
-  DecisionTreeFactor operator*(const DecisionTreeFactor& df) const override {
-    throw std::logic_error("Constraint::operator* not implemented");
-  }
-
-  /// Multiply with scalar just returns the constraint.
-  DiscreteFactor::shared_ptr operator*(double /* s*/) const override {
-    throw std::logic_error("Constraint::operator* not implemented");
-  }
-
   /// Multiply factors, DiscreteFactor::shared_ptr edition
   DiscreteFactor::shared_ptr multiply(
       const DiscreteFactor::shared_ptr& df) const override {
@@ -116,8 +104,6 @@ class GTSAM_UNSTABLE_EXPORT Constraint : public DiscreteFactor {
     return toDecisionTreeFactor().sum(keys);
   }
 
-  double max() const override { return 1.0; }
-
   DiscreteFactor::shared_ptr max(size_t nrFrontals) const override {
     return toDecisionTreeFactor().max(nrFrontals);
   }
diff --git a/gtsam_unstable/discrete/Domain.h b/gtsam_unstable/discrete/Domain.h
index b45b1f23e..6ce846201 100644
--- a/gtsam_unstable/discrete/Domain.h
+++ b/gtsam_unstable/discrete/Domain.h
@@ -114,11 +114,6 @@ class GTSAM_UNSTABLE_EXPORT Domain : public Constraint {
 
   /// Partially apply known values, domain version
   Constraint::shared_ptr partiallyApply(const Domains& domains) const override;
-
-  // Scale just returns the same constraint.
-  DiscreteFactor::shared_ptr scale() const override {
-    return std::make_shared<Domain>(*this);
-  }
 };
 
 }  // namespace gtsam
diff --git a/gtsam_unstable/discrete/SingleValue.h b/gtsam_unstable/discrete/SingleValue.h
index 152a8f51b..3df1209b8 100644
--- a/gtsam_unstable/discrete/SingleValue.h
+++ b/gtsam_unstable/discrete/SingleValue.h
@@ -77,11 +77,6 @@ class GTSAM_UNSTABLE_EXPORT SingleValue : public Constraint {
   /// Partially apply known values, domain version
   Constraint::shared_ptr partiallyApply(
       const Domains& domains) const override;
-
-  // Scale just returns the same constraint.
-  DiscreteFactor::shared_ptr scale() const override {
-    return std::make_shared<SingleValue>(*this);
-  }
 };
 
 }  // namespace gtsam