Relational Agenda Programming: A Uniform Execution Model for Embedded Reasoning Systems

Abstract

Most programming systems draw a hard boundary between the reasoning layer and the control layer, requiring a validation step at every interface and forcing programmers to maintain two models of their system simultaneously. We present Relational Agenda Programming (RAP), a uniform execution model in which reasoning, control flow, and I/O all flow through the same relational machinery with no privileged escape hatches. The key architectural choice is a virtual machine that executes goals via an explicit work queue, coupled with a pending-query agenda that is itself a first-class relational term. Queries receive the current agenda as input, reason over it using unification – the same machinery used for domain reasoning – and return a ChangeSet specifying atomic agenda modifications. ChangeSets are valid by construction: the no-ops and cons-ops constructors are relations that fail on invalid operations, so invalid ChangeSets cannot be expressed. We present a C++20 implementation with zero dependencies, embeddable via FFI from any language that supports C++ linkage. We validate the model through two small case studies and one larger, detailed example: embedded security policy verification demonstrating the Probe meta-evaluation primitive, reflective agenda reasoning demonstrating a query that inspects and modifies pending work through the same relational machinery used for domain reasoning, and a sustained adversarial reasoning task in which a hostile actor mutates shared state while the system maintains and repairs its relational belief state through continued reasoning over many rounds.