lib/dydx/algebra/set/symbol.rb in dydx-0.0.6 vs lib/dydx/algebra/set/symbol.rb in dydx-0.0.7

@@ -3,12 +3,12 @@
     module Set
       Symbol.class_eval do
         include Helper
 
         def differentiate(sym=:x)
-          self == sym ? _(1) : _(0)
+          self == sym ? e1 : e0
         end
         alias_method :d, :differentiate
       end
     end
   end
-end
\ No newline at end of file
+end