Trust as a Routing Container Minimal Executable Syntax for T3 in the 4-3-3-2 Grammar

This paper reframes the Canadian T3 trust return as a computable routing container within the 4-3-3-2 grammar and an X–Y fiscal framework. Rather than treating trust law as a dense doctrinal domain, it models T3 as an executable institutional object capable of staging both horizontal boundary shifts (cross-jurisdictional fiscal movement) and vertical intergenerational capacity flows. The paper compresses trust operations into a minimal routing kernel defined by three structural conversions—timing, type (character), and bearing-container—and two trigger classes: use change and title change. Discretion is rendered as an explicit execution variable bound to admissible records, transforming trustee intent from narrative context into a verifiable switch condition. Character is preserved through a null type conversion, formalizing T3 as a transparent relay within the 4-3-3-2 grammar. Execution is gated by Fiscal Epistemology (FE): without traceable evidence, no routing path exists. The result is an audit-grade model in which trust positions emerge as evidence-closed path objects rather than narrative conclusions. By converting T1–T2–T3 transitions into routable artifacts aligned to X-axis interfaces and Y-axis staging, the paper supplies a compact specification for workpaper alignment, reviewability, and scalable inspection in professional tax and assurance settings.