Can a trustee or beneficiary of a trust petition the probate court to determine the existence of the trust?

Under section 17200, subdivision (a), a " trustee or beneficiary of a trust may petition the court under this chapter concerning the internal affairs of the trust or to determine the existence of the trust." (See also Mota v. Superior Court (2007) 156 Cal.App.4th 351, 356, fn. 2.) Section 17200, subdivision (b), sets forth a nonexclusive list of "internal affairs." Included in this list are: "(1) Determining questions of construction of a trust instrument" and "(2) Determining the existence or nonexistence of any immunity, power, privilege, duty, or right." ( 17200, subd. (b)(1), (2).) Thus, section 17200 permits a trustee or beneficiary to petition the probate court for declaratory relief, seeking an affirmative interpretation of a trust or the powers of the trustee. Significantly, section 17200 is a permissive statute. It provides that an individual "may" proceed pursuant to its authority. It does not contain any language suggesting that a trial court is precluded from construing a trust instrument, or determining the rights of a settlor, in a proceeding brought under any other provision.