¶ 28. (concurring). I write separately because I find the "Initial applicability" sections of 2011 Wis. Acts 10 and 32 ambiguous. Nonetheless, I agree with the majority that these sections must be read to encompass not only the 2011-12 collective bargaining agreements (CBAs) but also the 2013-14 CBAs because to read them otherwise would result in inappropriate retroactive application of the acts when such application is not called for in the "express language" of the acts or by "necessary implication." Employers Ins. of Wausau v. Smith, 154 Wis. 2d 199, 224-25 n.21, 453 N.W.2d 856 (1990); Majority, ¶¶ 9, 23-25.
¶ 29. As the majority has explained, the matter at hand involves two separate sets of CBAs — one set for the period of 2011-12 and the other for the period of 2013-14 — and at the time Acts 10 and 32 were enacted only the 2011-12 CBAs were in effect, although both the 2011-12 and 2013-14 CBAs had been agreed to and executed. Majority, ¶¶ 1-2.
¶ 30. The initial applicability sections of the acts provide that each act "first applies to employees who are covered by a collective bargaining agreement... that contains [inconsistent provisions] ... on the day on which the agreement expires or is terminated, extended, modified, or renewed, whichever occurs first." 2011 Wis. Act 10, § 9332(1); 2011 Wis. Act 32, *178§ 9332(lq). As the majority correctly notes, neither act defines "covered by," and, I believe, both the City's and the union's facial readings of the initial applicability sections are reasonable.
¶ 31. Statutory interpretation begins with the statutory language itself, and if the meaning is plain the inquiry ends there. State ex rel. Kalal v. Circuit Court for Dane Cnty., 2004 WI 58, ¶ 45, 271 Wis. 2d 633, 681 N.W.2d 110. "In construing or interpreting a statute the court is not at liberty to disregard the plain, clear words of the statu te." Id., ¶ 46 (citation omitted). Rather, the statutory language is interpreted reasonably in the context in which it is used so as to avoid absurd or unreasonable results. Id. If a statute is "capable of being understood by reasonably well-informed persons in two or more senses," however, the statute is ambiguous, id., ¶ 47, and extrinsic sources may be consulted, id., ¶ 50.
¶ 32. To begin, I find dictionary definitions to be of little assistance. While it is true, as the majority states, that "covered by" can be read to mean "to ... take into account" or "to deal with," using the same dictionary as the majority, I observe that other definitions include "to afford protection against or compensation for," which could be read more favorably to the City's position. See Majority, ¶ 12; MERRIAM WEBSTER'S COLLEGIATE DICTIONARY 268 (10th red. 1997).
¶ 33. Likewise, a broader review of the initial applicability sections fails to clarify the legislature's intent. As the City notes, use of the words "a," "agreement," "contains," "expires," and "is" all suggest the initial applicability of the acts refers to employees covered by a single CBA, as opposed to multiple CBAs. If that were the legislature's intent, the single CBAs referred to most certainly would be those executed and *179in effect at the time the acts were enacted, here the 2011-12 CBAs, as opposed to those that may have been executed but not yet in effect. The former category unquestionably includes persons "covered by" a collective bargaining agreement. However, the majority points out that in Gowan v. McClure, 185 Wis. 2d 903, 912-13, 519 N.W.2d 692 (Ct. App. 1994), we said indefinite articles such as "a" do not necessarily imply a singular meaning because sometimes they "precede a noun when the thing named is not already known to the reader." Majority, ¶ 19. Here, it would be reasonable to read the initial applicability section in its actual singular form, and it would also be reasonable to read it as being potentially plural, in accord with Gowan, as the majority suggests. Without more, it would be arbitrary to choose one reading over the other. Thus, the initial applicability language — "first applies to employees who are covered by a collective bargaining agreement"— could reasonably be referring only to employees who are receiving benefits, i.e., who are "afford[ed] protection ... or compensation," from a CBA which is in effect, or it could be referring to employees who are included in, i.e., "take[n] into account" or "deal[t] with" in, an agreed upon and executed CBA, whether or not that CBA has yet gone into effect.1
¶ 34. Consideration of whether the acts have retroactive or prospective application resolves the ambiguity. A law operates retroactively if it "attaches new legal consequences to events completed before its enactment." Landgraf v. USI Film Prods., 511 U.S. 244, 269-70 (1994). Retroactive application is application that "would impair rights a party possessed when he acted, increase a party's liability for past conduct, or *180impose new duties with respect to transactions already completed." Id. at 280. There is a presumption against the retroactive application of law because it disturbs past transactions and is deemed incongruent with the concept of justice. Id. at 271 ("The largest category of cases in which we have applied the presumption against statutory retroactivity has involved new provisions affecting contractual or property rights, matters in which predictability and stability are of prime importance."). For a law to apply retroactively, the legislature must clearly indicate such intent "by express language or necessary implication." Employers Ins., 154 Wis. 2d at 224-25 n.21. And, as the majority has noted, when a statute is intended to apply retroactively, the question then becomes whether such application violates the state or federal constitutions. Majority, ¶¶ 9, 24; see Employers Ins., 154 Wis. 2d at 224; see also Allied Structural Steel Co. v. Spannaus, 438 U.S. 234, 249-51 (1978).
¶ 35. As evidenced by the ambiguity of the initial applicability sections, the legislature did not exhibit a clear intent to apply Acts 10 and 32 retroactively. Here, there is no express language stating that the acts should apply retroactively, and retroactivity is not "necessar[ily] impli[ed]" because either prospective or retroactive application could "work" under the acts (assuming the constitutionality of any retroactive application). Further, the legislature no doubt was aware when it enacted Acts 10 and 32 that municipalities and public sector unions across the state routinely enter into CBAs that, like many contracts, do not take effect until some future time period, yet it chose not to clearly specify whether the acts were intended to apply to such agreements. As the majority states, "When the legislature intends a law to upset settled contractual *181expectations, we expect a much clearer statement of such intention." Majority, ¶ 21. Due to the lack of clarity, the presumption against retroactivity remains, and the initial applicability sections of the acts can only be interpreted as applying the acts prospectively.
¶ 36. The City argues that a prospective application of the acts does not contravene its reading of "covered by" because what matters is whether the 2013-14 CBAs were "in effect" at the time the acts were enacted. To begin, the legislature chose to use the more ambiguous term "covered by," rather than "in effect." Further, the City cites to no authority for its position that the effective date of a contract, as opposed to the date of agreement and execution, is the date upon which parties become bound to one another and the terms of an agreement.2 Indeed, as the majority has pointed out, such a position would appear to fly squarely in the face of basic contract law, see Majority, *182¶¶ 14-15, as well as undermine the vital contractual goals of predictability and stability noted by the Supreme Court in Landgraf, 511 U.S. at 271. The date that matters for those purposes is the date on which both the City and the unions agreed to and executed the 2013-14 CBAs, and that date was prior to the enactment of the acts. Interpreting the acts in the manner the City requests would "attachf] new legal consequences to events completed before" the acts were adopted. See id. at 270. Thus, despite its arguments to the contrary, the City seeks retroactive application of the acts, something which the acts do not clearly call for.
¶ 37. In sum, 2011 Wis. Acts 10 and 32 can only be interpreted as applying to CBAs not yet agreed to and executed at the time those acts were enacted. To interpret the acts as applying to the 2013-14 agreements would require us to give the acts retroactive application, something the legislature did not clearly choose to do.
Our review of the legislative history of 2011 Wis. Acts 10 and 32 also fails to resolve the ambiguity.
All of the cases the City references to show application of an effective date involve contracts in which the effective date was prior to the date of execution. See, e.g., Beaudette v. Eau Claire Cnty. Sheriffs Dep't, 2003 WI App 153, ¶ 28, 265 Wis. 2d 744, 688 N.W.2d 133 (citing an Oregon Supreme Court case where the contract was agreed to and executed on August 24, 1953, but its effective date was April 1,1953); Garczyk v. United Steelw orkers, 763 F.2d 256, 258 (7th Cir. 1985) (contract agreed to and executed on November 1,1977, but its effective date was August 1, 1977); cf. Flynn v. Interior Finishes Inc., 425 F. Supp. 2d 38, 46 (D.D.C. 2006) (stating that parties can become bound on a "date before (or after) the date on which they actually signed the agreement," but addressing agreement that was executed after effective date). The singular lesson of these cases related to our question of the prospective/retroactive application of a statute is that the effective date becomes pertinent when it is earlier than the date of execution. This notion is in accord with the equitable principles noted in Landgraf v. USI Film Prods., 511 U.S. 244, 271 (1994).