How is an endowment construed when there is mixed use of conjunctions ('and') and sequencing terms?

Primary text

When the settlor mixes sequencing with conjunctions (like 'wa' - and), the ruling follows the specific phrasing. If the wording is 'upon my children, and the children of my children, then upon their children,' the use of 'and' between the first two groups implies they share the benefit initially. Only after that initial group is extinct does the benefit pass to the subsequent group specified by the sequencing particle ('then'). If the phrasing is 'upon my children, then upon the children of my children, and their children,' the children alone benefit first; upon their extinction, the benefit becomes shared among those succeeding them. If the wording is 'upon my children and the children of my children, then upon their children and the children of their children,' the first two generations share the benefit jointly, excluding others, until they become extinct, at which point the benefit passes to the subsequent generations.