--- a/macros.xml	Tue May 19 07:05:36 2015 -0400
+++ b/macros.xml	Wed May 27 12:54:35 2015 -0400
@@ -89,10 +89,6 @@
         </param>
     </xml>
 
-    <xml name="choose_column">
-        <param name="col" type="data_column" data_ref="input" label="Specify the column(s) that should be summarized" help="(-c)" />
-    </xml>
-
     <token name="@C_AND_O_ARGUMENT@">
         #set $col = list()
         #set $op = list()
@@ -108,7 +104,7 @@
 
     <xml name="c_and_o_argument">
         <repeat name="c_and_o_argument_repeat" title="Applying operations to columns from merged intervals" min="0">
-            <expand macro="choose_column" />
+            <yield />
             <expand macro="choose_operations">
                 <expand macro="math_options" />
                 <expand macro="additional_math_options" />