4 files changed, 1 insertions, 13 deletions
diff --git a/lib/arel/engines/sql/core_extensions/nil_class.rb b/lib/arel/engines/sql/core_extensions/nil_class.rb
index d4bb0e4c33..ab990d6211 100644
--- a/lib/arel/engines/sql/core_extensions/nil_class.rb
+++ b/lib/arel/engines/sql/core_extensions/nil_class.rb
@@ -9,10 +9,6 @@ module Arel
         'IS NOT'
       end
 
-      def not_predicate_sql
-        'IS NOT'
-      end
-
       NilClass.send(:include, self)
     end
   end
diff --git a/lib/arel/engines/sql/core_extensions/object.rb b/lib/arel/engines/sql/core_extensions/object.rb
index 5415c84706..01c3c5479d 100644
--- a/lib/arel/engines/sql/core_extensions/object.rb
+++ b/lib/arel/engines/sql/core_extensions/object.rb
@@ -13,10 +13,6 @@ module Arel
         '!='
       end
 
-      def not_predicate_sql
-        '!='
-      end
-
       Object.send(:include, self)
     end
   end
diff --git a/lib/arel/engines/sql/predicates.rb b/lib/arel/engines/sql/predicates.rb
index df8700a500..59b0ab0929 100644
--- a/lib/arel/engines/sql/predicates.rb
+++ b/lib/arel/engines/sql/predicates.rb
@@ -52,7 +52,7 @@ module Arel
       end
     end
 
-    class Inequality < Equality
+    class Inequality < Binary
       def predicate_sql
         operand2.inequality_predicate_sql
       end
diff --git a/lib/arel/engines/sql/primitives.rb b/lib/arel/engines/sql/primitives.rb
index 41769fa510..15a27b2256 100644
--- a/lib/arel/engines/sql/primitives.rb
+++ b/lib/arel/engines/sql/primitives.rb
@@ -42,10 +42,6 @@ module Arel
       value.inequality_predicate_sql
     end
 
-    def not_predicate_sql
-      value.not_predicate_sql
-    end
-
     def to_sql(formatter = Sql::WhereCondition.new(relation))
       formatter.value value
     end