Had I instead assumed that the Excess Treaty was inuring to the Pro-Rata Treaty, the primary insurer would have been responsible for an additional 0.6M (1.5M x 0.4 = 0.6M, excluding Excess Treaty's share of this layer). Is there ever a situation where I should be assuming that one treaty is inuring to another, or better to always assume not unless otherwise stated (ex. with interlocking clause)? If assumptions need to be made, is there a conventional "order of operations" if not explicitly stated (i.e., first apply excess coverage, then pro-rata coverage, etc.)?