¶ 41. (concurring). The majority adopts the approach of the concurring opinion in Bidlack v. Wheelabrator Corp., 993 F.2d 603, 611 (7th Cir. 1993)(en banc)(Cudahy, J., concurring) as the analytical framework for determining whether retirement welfare benefits in collective bargaining agreements are vested. I would adopt the approach of the lead opinion in Bidlack, and therefore concur.
¶ 42. As the majority notes, the lead opinion in Bidlack retreated from Senn s1 bright-line approach regarding vesting language in collective bargaining agreements, establishing instead an analytical approach to the question that focuses on traditional rules of contract interpretation while maintaining an initial presumption that rights and obligations cease upon the expiration of the contract. Id. at 607. The concurrence applauded the retreat, but would have gone further to apply a different initial presumption: that benefits vest and therefore continue beyond the expiration of the contract, unless otherwise specifically stated. Id. at 613 (Cudahy, J., concurring). Apparently, the concurrence would have overruled Senn, and in fact went so far as to say that"Senn and its default rule now *190do seem. . .to be a dead letter." Id. at 610 (Cudahy, J., concurring).
¶ 43. Bidlack involved a class action suit filed by retired employees of the Wheelabrator Corporation. The lead opinion, by Chief Judge Richard Posner, framed the question presented by the case in this way:
[W]hether the absence from the collective bargaining agreements of any provision that explicitly vests the health benefits of retired employees defeats those employees' claims even though some contractual language and a great deal of 'extrinsic' evidence — evidence apart from the language of the agreements — suggest that the parties may have intended to confer vested rights on the retired employees, that is, rights that would outlast the expiration of the last collective bargaining agreement.
Id. at 605.
¶ 44. The Wheelabrator collective bargaining agreements stated that "those employees who have retired since September 22,1959, will have the full cost of their Blue Cross-Blue Shield coverage paid by the Company after they attain sixty-five (65) years of age," and that the benefits "shall be continued for the spouse after the death of the retiree." Id. at 605. As in this case, the district court in Bidlack concluded that the employer was entitled to summary judgment because the language of the agreements did not explicitly state that the benefits vested at retirement. Arndt v. Wheelabrator Corp., 763 F. Supp. 396, 404, 406 (N.D. Ind. 1991). The en banc Seventh Circuit reversed.
¶ 45. Judge Posner began his analysis with the following general observation: "[OJrdinarily when a contract expires, it — expires. It is at an end. The parties have no more rights or duties under it. Sometimes, *191however, a contract creates entitlements that outlast it." Bidlack, 993 F.2d at 606. The trick, of course, is determining which are the determinate rights or obligations and which are the indeterminate ones.
¶ 46. The starting point is the presumption, deriving from the foregoing basic principle, that because it has a fixed term, "a collective bargaining agreement ceases to obligate the employer when the agreement's term.. .is up." Id. at 607. The lead opinion in Bidlack, therefore, left Senn s basic presumption in place. But the court went on to note that "it is not an irrebuttable presumption. 'Rights which accrued or vested under the [collective bargaining] agreement will, as a general rule, survive termination of the agreement.' The question is what it takes to rebut the presumption." Id. (citation omitted).
¶ 47. The Bidlack court then rejected two interpretive extremes: 1) that to rebut the presumption that benefits expire when the agreement expires (in other words, do not vest), the contract must either use the word "vest" or other similarly unequivocal language; and 2) that to rebut the presumption the parties can freely substitute testimony regarding the parties' intentions for contractual language indicative of intent. Id. The court said the former approach would institute excessive formalism and the latter would deprive parties of the protection of a written contract. Id.
¶ 48. The Bidlack court concluded, and I agree, that in this context, as in all contract cases, the court should look first to the four corners of the contract itself for evidence to rebut the initial presumption that the obligation expires when the contract does. If the contract language unambiguously confirms the presumption — or overcomes it — the analysis is over, *192and the court must apply the contract as written. To overcome the presumption, however, the word "vest" (or similar equivalent) need not necessarily appear, if the intent to establish a right which survives the expiration of the agreement is otherwise clear from the language used and the overall language and logic of the contract. Id. ("[W]e do not think that a court should refuse to enforce a contract merely because the parties have failed to use a prescribed formula").
¶ 49. If, however, the contract is ambiguous, the court may look to extrinsic evidence to attempt to determine the parties' intent. The Bidlack court cautioned, and I would too, that ambiguity cannot be created by extrinsic evidence:
[T]he use of extrinsic evidence to create such obligations [to pay lifetime medical benefits] nowhere alluded to in the contract would unjustifiably deprive the parties of the limitation of liabilities that is implicit in the negotiation of a written contract having a definite expiration date. Subject only to the limited protection against unforeseeable contractual obligations that is conferred by the doctrine of impossibility, a party might find itself saddled with obligations for the next twenty or thirty years (or even more, in the case of a surviving spouse's benefits) even though it had reasonably believed that all its obligations would end in three years, when the contract expired by its own terms. Although extrinsic evidence is admissible to show that a written contract which looks clear is actually ambiguous, perhaps because the parties were using words in a special sense, there must be either contractual language on which to hang the label of ambiguous or some yawning void. . .that cries out for an implied term. Extrinsic evidence should not *193be used to add terms to a contract that is plausibly complete without them."
Id. at 608 (citations omitted)(emphasis supplied). The parol evidence rule also provides a limitation on the use of extrinsic evidence. Id. (["T]he parol evidence rule.. .enforces integration clauses by barring evidence of side agreements, [although it] does not bar the use of extrinsic evidence to clarify the meaning of an ambiguous text"). Finally, if the agreement is completely silent about the duration of the benefits, and there is nothing in the logic, structure or other provisions of the contract that suggests that the benefits were meant to survive the expiration date, resort to extrinsic evidence is improper. Id.
¶ 50. Ultimately, if an examination of relevant and admissible extrinsic evidence fails to clarify the contractual ambiguity, the court may resort to the application of a default rule of contract interpretation. Id. at 609. Judge Posner clarified what is meant by "default rule," and when it is appropriate to invoke one:
The contract, even when its logic and its other provisions as well as just the provision in issue are considered, is inconclusive on the question whether it confers an entitlement to health benefits that outlasts the contract's expiration date. A completely intractable issue of contract interpretation can be resolved only by the application of some default rule — a burden of persuasion, a clear-meaning rule, a presumption based on the authorship of the contract. But the time to throw up one's hands and apply such a rule is after extrinsic evidence has been considered. For until then, we do not know whether we have an intractable interpretive issue or merely an issue that cannot be resolved without *194testimony or other evidence besides the language and logic.. .of the contract.
Only a posture, not easy to reconcile with the Seventh Amendment, of extreme mistrust of juries would entitle us to pretermit a factual inquiry and apply an interpretive canon or other tie-breaker before we know that the sides are actually tied.
Id.
¶ 51. Senn and the concurrence in Bidlack had referred to the initial presumption as a "default rule," which, as this passage of the lead opinion in Bidlack makes clear, is technically incorrect. The initial "no-vest" presumption is a creature of the contract itself, because it has a limited term, and applies at the beginning of the interpretive process. It may be overcome by other contract language indicative of an intent to grant a lifetime benefit, or extrinsic evidence (if the contract language is vague) or both. A "default rule," properly understood, is a judicial canon of contract construction (such as the rule that we construe contracts against the drafter) that applies only in the event of an unresolvable ambiguity — a tie — and only at the end of the process after extrinsic evidence has failed to clear up the question.
¶ 52. The initial presumption of vesting proposed by the Bidlack concurrence and adopted by the majority in this case represents a policy preference that I share but am constrained by the law of contracts from imposing upon the parties to a written, limited-term collective bargaining agreement. The contract sets the rights and liabilities of the parties, not the policy preferences of this court.
¶ 53. The majority relies in part on the policy articulated in Schlosser v. Allis-Chalmers Corp., 86 Wis. 2d 226, 271 N.W.2d 879 (1978). However, as both *195lower courts concluded, Schlosser is fundamentally factually distinguishable. There, the retirees had been salaried, nonunion employees whose employment arrangement with Allis-Chalmers was ongoing, open-ended and had no fixed expiration date. The court essentially construed the insurance benefits at issue in that case as a part of the open-ended employment agreement when it held that the benefit level at the time of retirement vested and could not be unilaterally modified later. Here we have a series of fixed-term collective bargaining agreements that were continually renegotiated upon expiration.
¶ 54. It is one thing to find that a continuing obligation of indefinite duration (free life insurance for life in Schlosser) vests upon retirement under a continuing, open-ended contract which is itself of indefinite duration. It is another thing to find that an indefinite, continuing obligation (free health insurance for life in this case) vests upon retirement and therefore survives the expiration of a fixed-term collective bargaining agreement, the obligations of which otherwise terminated when the contract did. Schlosser's rationale of retirement welfare benefit vesting cannot be readily transplanted into the collective bargaining context.
¶ 55. Accordingly, I would adopt the analysis of the lead opinion in Bidlack and remand to the circuit court to apply it.2 Therefore, I respectfully concur.
*196¶ 56. I am authorized to state that Justices JON P. WILCOX and DAVID T. PROSSER join this concurring opinion.
Senn v. United Dominion Industries, 951 F.2d 806, 814-16 (7th Cir. 1992).
For examples of post-Bidlack cases applying its analysis, see Pabst Brewing Company, Inc. v. Corrao, 161 F.3d 434 (7th Cir. 1998); Diehl v. Twin Disc, Inc., 102 F.3d 301 (7th Cir. 1996); Murphy v. Keystone Steel & Wire Co., 61 F.3d 560 (7th Cir. 1995); Rossetto v. Pabst Brewing Company, Inc., 71 F.Supp.2d 913 (E.D. Wis. 1999).