There was a will which established a sprinkling trust of the entire residuary estate with income in the trustee's discretion payable to the testatrix's son, Robert, and any of his issue, with principal invasion on limited terms for the benefit of the son, and any child or grandchild of the son. The trust was to terminate on the death of the son and his two children, Ian and Zara with the principal and all accrued and accumulated income to be paid to the issue of the decedent's son living at the termination of the trust per stirpes. Both Ian and Zara have children of their own. The issue of virtual representation was before the court on the three great-grandchildren. Petitioner's argument is based on the theory that the grandchildren and the great-grandchildren have the requisite same interests under the virtual representation statute; the maximization of trust principal and therefore their interests are not in conflict.