On September 24, 1975 defendant gave a sworn statement to a member of the New York State Police detailing his involvement in the trafficking of illegal drugs with one Michael Cunningham who was then under indictment. Pursuant to a subpoena, defendant was called as a prosecution witness to testify at the Cunningham trial in January of 1976. Although the prosecution attempted to elicit testimony from him about the purchase of drugs from Cunningham in conformity with his earlier statement, defendant refused to answer certain questions, invoking his Fifth Amendment privilege, and, among other responses, swore that he had only purchased jewelry from Cunningham. The prosecution con*68tended that this testimony and the statement previously obtained were irreconcilably inconsistent, thereby proving the crime of perjury in the second degree (Penal Law, §§ 210.20, 210.10), and the jury agreed.
The two accounts were plainly incompatible as a legal proposition (People v Dunleavy, 41 AD2d 717, affd 33 NY2d 573), and defendant’s efforts to explain those inconsistencies and harmonize one with the other merely presented issues of fact for resolution by the jury (see People v Grier, 42 AD2d 803). We not only find the proof sufficient to establish defendant’s guilt beyond a reasonable doubt and the jury’s verdict consistent with the weight of the evidence, we believe that the record discloses overwhelming support for its conclusion. Given the short time interval separating the two accounts and the unequivocal nature of his answers on each occasion, it cannot be seriously maintained that the differences between the two reflected a fallible memory or confusion on defendant’s part (cf. People v Samuels, 284 NY 410; People v Lombardozzi, 35 AD2d 528, affd 30 NY2d 677). Each of defendant’s versions was clear and purposeful and at neither time can it be said that he had been tricked into giving unintended responses (People v Trozzo, 34 NY2d 836).
Defendant also claims that his testimony at the Cunningham trial was improperly received into evidence against him; that his written statement of September 24, 1975 was not one for which an oath was required by law so as to support a second degree perjury conviction; and that he was improperly sentenced as a second felony offender. We reject these arguments.
A suppression hearing was conducted concerning the written and testimonial statements and the record supports the findings of the voluntary character of each beyond any doubt. Defendant was counseled by two retained attorneys before the written statement was given and he was presented with the opportunity of consulting with a lawyer of his own choice before testifying at the Cunningham trial. The suggestion that the admission of either account into evidence at his perjury trial violated any constitutional rights is totally without foundation (United States v Mandujano, 425 US 564).
Among other elements, second degree perjury requires that one swear falsely in a written instrument for which "an oath is required by law” (Penal Law, § 210.10). Such an oath is required for a written instrument when "absent an oath or *69swearing thereto, it does not or would not, according to statute or appropriate regulatory provisions, have legal efficacy in a court of law or before any public or governmental body, agency or public servant to whom it is or might be submitted.” (Penal Law, § 210.00, subd 4.) Defendant contends that his sworn statements of September 24, 1975 did not require an oath under that definition and relies on People v Lillis (3 AD2d 44) in support of his argument. We disagree. In Lillis the defendant contradicted a written statement he had given under oath to an investigator for the State Liquor Authority. As that decision points out, however, the execution and form of such statement was not regulated by law and the annexation of an oath added nothing to its legal effect (People v Lillis, supra, p 47). Here, by way of contrast, the defendant was on trial for drug related offenses when the proceedings were interrupted upon his agreement to give a subscribed written instrument, under oath, about his involvement with Cunningham. He denied that he further promised to testify against Cunningham at a later date, but does not dispute the understanding that his oath would support that statement. On September 23, 1975 defendant was allowed to plead guilty to the least serious charge then pending against him in satisfaction of the indictment and, after completing the statement, was ultimately sentenced to the minimum period of incarceration mandated for that conviction. In short, the giving of a sworn statement was one of the terms attached to the bargain voluntarily struck by defendant as part of the negotiations which led to his conviction. It can hardly be imagined that his plea would have been accepted by the trial court, or that it would have fulfilled the sentencing agreement, had defendant repudiated that bargain and supplied authorities with an unsworn account. Defendant’s oath was crucial to the plea negotiations and his statement would not have possessed legal efficacy without it. True, that oath was not expressly required by statute or appropriate regulatory provision, but we decline to interpret those terms as narrowly as defendant would have us read them. The condition that an oath accompany defendant’s statement was in accordance with plea bargaining practices of long-standing and common acceptance in situations such as this one. A trial court has implicit authority to approve the terms under which it will accept guilty pleas and we do not think that the evident purpose of the statute should be restricted by insisting on the adoption of a mechanical regulation to cover this subject (see People v Martin, 175 NY 315; People v Joseph, 173 Misc 410).
*70Lastly, as to the question of sentence, defendant could only be treated as a second felony offender if the sentence for his drug conviction was imposed before the perjury was committed (Penal Law, § 70.06, subd 1, par [b], cl [ii]). Since that sentence was imposed before defendant testified at the Cunningham trial, the issue becomes one of determining when the perjury was committed under the statute permitting proof thereof by means of inconsistent statements without designating the falsity of either (Penal Law, § 210.20). We can agree that the period of limitation began to run on September 24, 1975 (see People v Lohnes, 76 Misc 2d 507), but that does not answer our inquiry for the statement given on that date may well have been true. Perjury could not have been charged under the theory utilized by the prosecution in this case until some falsity was manifested by defendant’s subsequent inconsistent testimony. By then, of course, defendant already stood convicted of a predicate felony. Under these circumstances, we conclude that the perjury, as alleged, was not committed until the inconsistency appeared and, therefore, defendant was properly sentenced as a second felony offender.
The judgment should be affirmed.