The International Association of Machinists (the union) was the bargaining agent for the employees of Powder Power Tool Corporation.

On August 24, the union and the corporation executed a collective bargaining agreement providing for retroactively increased wage rates for the corporation's employees effective as of the previous April 1.

Three employees who were working for Powder before and for several months after April 1, but who were not employed by the corporation when the agreement was executed on August 24, were paid to the time their employment terminated at the old wage scale. The three employees assigned their claims to Springer, who brought this action against the corporation for the extra wages. Decision?