(decedent created a trust and "pour-over" will; trust divided into two trusts upon death for benefit of surviving spouse; upon death of surviving spouse remaining assets of trusts combined with 50% passing in trust to the then-living descendants of the decedent's two children; however any descendant who married outside of the Jewish faith or whose non-Jewish spouse did not convert to Judaism within one-year of marriage would be deemed deceased as of the date of the marriage and such share would revert to such descendant's parent (child of the decedent); clause language upheld - decedent entitled to distribute his property as he deemed appropriate and favor grandchildren who made choices of which the decedent approved).