The special guardian appeals from an order, insofar as it reforms a trust indenture so as to permit revocation thereof by the petitioner-respondent, who was the trustor, on the consents of two named persons, and revokes the indenture. Order modified on the law and the facts by striking therefrom the first, second, fourth and fifth ordering paragraphs, and by providing in lieu thereof that the application be denied. As so modified, order unanimously affirmed, with separate bills of costs to the special guardian and to the respondent Bessemer Trust Company. Findings of fact inconsistent herewith are reversed and new findings are made as indicated herein. A voluntary irrevocable deed of trust may not be vacated by the trustor on the ground that at the time of the execution of the document he believed that it was revocable, "except upon clear proof of the trustor's misunderstanding of the nature of the paper executed" ( Ludlam v. Ludlam, 194 App. Div. 411, 413, affd. 232 N.Y. 615). The petitioner failed to establish the required proof.