Final answer:
Bill Bass's extension of his bridge's anchorings onto his neighbor's land is referred to as an easement, which is a right to use property owned by someone else. Legal permission may be required for such an action, and disputes could arise leading to a need for an easement agreement or legal resolution.
Step-by-step explanation:
When Bill Bass builds a bridge across a stream and the anchorings for the bridge extend onto his neighbor's land, the situation is typically referred to in legal terms as an easement. An easement is a right that allows someone to use part of a property that he or she does not own. In this particular case, if Bill Bass has not gained legal permission to extend his bridge onto the neighbor's property, he could be seen as imposing an easement without consent, which can lead to legal disputes.
Resolving such a dispute often involves legal processes and can potentially require Bill to seek an easement agreement with his neighbor, possibly involving compensation or other terms agreed upon by both parties. Should they not reach an agreement, it may be necessary to engage in a legal process, potentially involving the local government or courts to determine the legality and conditions of the easement for the bridge's anchorings.