Inferring others' beliefs requires more than reading surface signals; it requires tracking who told them what, in what order, and how credibly. The Theory of Mind Utility (ToM-U) formalizes this epistemic state inference problem at the computational level of analysis, specifying what mentalizing computes and why without commitment to algorithmic or neural implementation. ToM-U achieves this by constructing Local Epistemic World Models (LEWMs) -- directed typed graphs that represent agents, state nodes, and the epistemic relationships among them -- and evaluating discrete candidate LEWMs against observed behavior until one achieves sufficient confidence. Five formal definitions specify the LEWM structure, agent node properties including ordered information access history, a bounded proliferation mechanism for recursive mentalizing, three inference procedures, and a residue function that captures the structured trace left by failed mentalizing attempts. ToM-U differs from Bayesian Theory of Mind and adjacent formal accounts, which presuppose rather than derive belief states, and from simulation theory and theory-theory, which lack a formal apparatus for epistemic state inference. The architecture generates directional, falsifiable predictions about mentalizing failure that follow from structural properties of the model rather than auxiliary assumptions, and positions ToM-U as a domain-agnostic mechanism upstream of goal inference and other downstream social cognitive processes.

翻译：推断他人信念需要超越表面信号解读，而需追踪信息传递者、传递顺序及信息可信度。心理理论效用（ToM-U）在计算分析层面形式化定义了这种认知状态推断问题，明确了心理化机制的计算内容与目标，但不涉及算法或神经实现的具体方案。ToM-U通过构建局部认知世界模型（LEWMs）来实现这一目标——该模型采用有向类型图表示智能体、状态节点及其认知关系——并通过比对离散候选LEWMs与观察行为，直至获得足够置信度为止。五条形式化定义分别规范了：LEWM结构、包含有序信息访问历史的智能体节点属性、递归心理化的有限增殖机制、三种推理程序，以及捕捉失败心理化尝试的结构性痕迹的残差函数。ToM-U不同于贝叶斯心理理论及相关形式化方法（后者预设而非推导信念状态），也与模拟论和理论论存在本质区别（后者缺乏认知状态推断的形式化工具）。该架构能基于模型结构属性（而非辅助假设）生成关于心理化失败的定向可证伪预测，将ToM-U定位为独立于领域、先于目标推断及其他下游社会认知加工过程的机制。