In In re Arthur N. (1976) 16 Cal.3d 226, a case involving a supplemental petition charging the commission of a new crime (robbery) as the basis for committing the juvenile to CYA, the Supreme Court held that due process requires proof beyond a reasonable doubt to establish the misconduct alleged in a section 777 supplemental petition. (Id. at p. 240.) However, the holding of Author N. is limited to situations "'where the supplementary petition charges new and different criminal acts not included in the original petition.'" (In re Eddie M., 100 Cal.App.4th at p. 1243.) "Adoption of the requirement of proof beyond a reasonable doubt for all supplemental petition hearings was the result of a change in court rules, not constitutional decision." (Ibid.) The Court rejected as "superficial" the asserted similarity between proceedings under former section 777 and adult probation violation hearings. (Arthur N., supra, 16 Cal.3d at p. 236.) "Unlike adult criminal proceedings in which probation may be granted as an act of leniency in appropriate cases, but where denial or probation and imposition of sentence to a term of imprisonment is ordinarily not an abuse of discretion, the Juvenile Court Law '"contemplates a progressively restrictive and punitive series of disposition orders in cases such as that now before us -- namely, home placement under supervision, foster home placement, placement in a local treatment facility and, as a last resort, Youth Authority placement."' Thus, while the adult whose probation is revoked may not be subjected to any greater punishment than that provided for the original offense, a juvenile adjudged a 601 ward as the result of noncriminal conduct, and a 602 ward adjudged so on the basis of a minor offense, may be removed from the parents' home and subjected to increasingly severe and restrictive custody which exceeds that which would have been permissible initially, if he is later found on a supplemental petition to have committed additional acts of misconduct. For this reason, respondent's suggestion that a hearing on a supplemental petition is a hearing on 'disposition,' not subject to the reasonable doubt standard, rather than an 'adjudicatory hearing' cannot withstand scrutiny." ( Arthur N. 16 Cal.3d at p. 237.) In distinguishing the consequences of sustaining a supplemental petition under former section 777 from those resulting from adult probation revocation proceedings, the Court also emphasized that confinement at CYA is "not limited to a period that is proportionate to the original act or acts of misconduct or criminal behavior upon which jurisdiction over the minor was first asserted." (In re Arthur N., supra, 16 Cal.3d at pp. 238-239.) The failure to advise the minor of his appeal rights, as required by California Rules of Court, rule 251, was held to be a violation of equal protection, and the court examined the diligence used to pursue his appeal rights once he learned of those rights. Even though the notice of appeal was filed almost three months late in that case, the appeal was held timely because the minor proceeded diligently after being advised of his appeal rights.