Grassroots Logic Programs (GLP) is a concurrent logic programming language with paired reader/writer variables, designed for grassroots distributed platforms. Concurrent (cGLP) and multiagent (maGLP) nondeterministic operational semantics have been presented in prior work. Here we present madGLP, a deterministic counterpart of maGLP in which agents communicate solely by message passing, and prove it correctly implements maGLP. The key technical insight is that maGLP shared variable pairs spanning agents can be implemented as local variable pairs connected by global links, with correctness following from disjoint substitution commutativity (a consequence of GLP’s single-occurrence invariant). We further prove that madGLP is grassroots. madGLP serves as the formal specification for an AI-driven implementation discipline (math → informal spec → Dart) employed and described here: from a single-agent specialization, AI (Claude) developed a workstation-based GLP implementation in Dart, and from madGLP it is developing a smartphone-based multiagent one.