Noting the undesirability of determining the conscious objective of a union in obtaining the inclusion of a challenged provision in a collective bargaining agreement on a bare stipulation of facts which supplies no indication of purpose or intention beyond the language of the provision and the general bargaining history
In A. Duie Pyle we noted that it is "undesirable to determine the conscious objective of a union in obtaining the inclusion of a challenged provision... on a bare stipulation of facts."