OPINION OF THE COURT
Asch, J.The parties to this action were married in 1945 and have two children. In 1973 the defendant husband obtained a divorce decree from plaintiff in the Dominican Republic and thereafter remarried. In 1978 the plaintiff commenced the instant action, seeking inter alia, a judicial declaration that she was the lawful wife of defendant; that the purported judgment of divorce obtained by defendant was null and void; and that the purported marriage of defendant and another woman was null and void. Plaintiff did not seek to terminate or alter her marriage by requesting divorce, annulment or separation. In November, 1981, plaintiff moved to discontinue this action without prejudice *397so that she might commence a new action against defendant for divorce. This new action would seek relief pursuant to the Equitable Distribution Law (Domestic Relations Law, § 236), passed by the Legislature after the initial action was instituted and before her motion to discontinue was made. Defendant opposed the application, to the extent it allowed plaintiff to seek equitable distribution relief, asserting that equitable distribution is unavailable in any action commenced prior to July 19, 1980, the effective date of the Equitable Distribution Law.
Special Term granted plaintiff’s motion to discontinue pursuant to CPLR 3217 (subd [b]). In so doing, it correctly observed that the instant complaint does not fall within the scope of part A of section 236 of the Domestic Relations Law.
Section 236 of the Domestic Relations Law provides: “Except as otherwise expressly provided in this section, the provisions of part A shall be controlling with respect to any action or proceeding commenced prior to [July 19, 1980] and the provisions of part B shall be controlling with respect to any action or proceeding commenced on or after such effective date”.
Section 236 (part A, subd 1) of the Domestic Relations Law provides, in pertinent part: “In any action or proceeding brought (1) during the lifetime of both parties to the marriage to annul a marriage or declare the nullity of a void marriage, or (2) for a separation, or (3) for a divorce”. Not all “matrimonial” actions are included in these categories. Part A does not apply to an action for a declaratory judgment with respect to the validity of a marriage — the action discontinued herein. On the other hand, section 236 (part B, subd 2) provides that “the provisions of this part shall be applicable to actions for an annulment or dissolution of a marriage, for a divorce, for a separation * * * for a declaration of the validity or nullity of a marriage, and to proceedings to obtain maintenance or a distribution of marital property following a foreign judgment of divorce, commenced on and after the effective date of this part” (emphasis added).
Thus, although plaintiff’s pending action is not among those enumerated by the Legislature to be within the scope *398of part A, it is expressly included in the provisions of part B. Clearly the Legislature intentionally excluded the relief plaintiff sought in the instant action from the controlling provisions of part A by not enumerating it with the others. “When different terms are used in various parts of a statute or rule, it is reasonable to assume that a distinction between them is intended” (Matter of Albano v Kirby, 36 NY2d 526, 530). Special Term correctly invoked the rule of expressio unius est exclusio alterius which stands for the proposition that where a law expressly describes a particular act, thing or person to which it shall apply, an inference should be drawn that what is omitted or not included was intended to be omitted or excluded (see Patrolmen’s Benevolent Assn. of City of N. Y. v City of New York, 41 NY2d 205, 208-209).
The dissent relies upon Tucker v Tucker (55 NY2d 378) and Valladares v Valladares (55 NY2d 388). These cases are, however, distinguishable. In Tucker, the plaintiff wife commenced an action for divorce prior to the enactment of the Equitable Distribution Law. She sought an award of alimony as part of her relief. The husband began his own separate action for divorce two weeks prior to the change in the law. After July 19,1980, the wife moved to discontinue her action in order to institute a second action to obtain the benefits of the property distribution provisions of part B of section 236. The Court of Appeals found that the wife could not discontinue her initial action for the purpose of instituting a new action taking advantage of the benefits of the new law.
In Tucker {supra), unlike the instant case, the plaintiff had already commenced an action for divorce and alimony prior to the effective date of the new law. Such relief is specifically provided for in part A. In the case at bar, plaintiff’s action has no relation to the specific actions enumerated in part A.
Similarly in Valladares {supra) the defendant wife had interposed a counterclaim in an action for divorce which was commenced prior to July 19, 1980. She was denied leave to amend her answer to demand distribution of the marital property. Again, unlike the situation in Valladares {supra) there is no action for divorce pending herein. *399Neither plaintiff nor defendant in this matter commenced any action or proceeding described in part A of section 236 prior to July 19, 1980.
Zuckerman v Zuckerman (56 NY2d 636) and Pollack v Pollack (56 NY2d 968) are also inapposite since both dealt with plaintiffs seeking to discontinue actions for divorce so that they could commence new actions pursuant to part B of section 236.
As this court has previously stated: “It is virtually impossible to state as a general proposition and as a matter of law that all prior matrimonial actions, whenever commenced and without regard to whatever action may have been taken, preclude a subsequent application for equitable distribution treatment under part B of section 236 of the Domestic Relations Law. Each case must be resolved on the basis of the facts and circumstances presented.” (Broder v Broder, 91 AD2d 302, 306.)
The facts herein show a complaint for declaratory judgment with respect to the validity of a marriage which is clearly outside the boundaries set for part A of section 236 actions. Plaintiff is not precluded therefore, under the circumstances herein, from discontinuing this action and commencing an action pursuant to the provisions of part B of section 236.
Accordingly, the order of the Supreme Court, New York County (Gabel, J.), entered December 14, 1982, granting plaintiff’s motion pursuant to CPLR 3217 (subd [b]) to discontinue the pending action without prejudice to commencing a new action for divorce seeking, inter alia, equitable distribution relief, should be affirmed without costs.