agreement has been signed by and between the employer and the workmen, in such manner, as may be prescribed and a copy thereof has been sent to the appropriate Government and the conciliation officer. Under Section 18(1), a settlement arrived at between employer and the workmen otherwise than in the course of conciliation proceeding binds the parties to the agreement. The proviso to Section 18(1) envisages that where there is a recognized union for any undertaking then such agreement, not being an agreement in respect of dismissal, discharge, removal, retrenchment, termination of service, or suspension of an employee, shall be arrived at between the employer and the recognized Union only and such agreement shall be binding on all persons referred to in clauses (c) and (d) of sub-section (3) of the said Section. Under Clause (c) of subsection (3) the settlement binds the heirs, successors or assignees of the employer. Under Clause (d) the settlement binds all persons, who were employed in the establishment or part of the establishment, as the case may be, to which the dispute relates on the date of the dispute and all persons, who subsequently become employed in that establishment or part.