Strict Role Alternation: Reciprocal Broadcast Without Relayers for Shielded Pools on the EVM

Contents of this record- strict_role_alternation_v0.4.pdf / .md: the paper (English, primary).- related_work_locomotive_wagon_v0.1.pdf / .md: annex on prior art across scrip systems, incentives in anonymity networks and relayer designs.- tractor_vagon.py (v0.3, SHA-256 e55249d7…ee64e47): population simulator, Python 3 standard library only; released under the MIT license (LICENSE_tractor_vagon.txt). Command-line flags are in Spanish; the paper's Reproducibility section maps them.- SHA256SUMS.txt: hashes of every file. ReproducibilityEvery figure in Section 7 is produced by one command listed in the Reproducibility section; all runs use seed 1 except the robustness series. Versions 0.1 and 0.2 of the simulator produce byte-identical output for the commands that predate them. StatusTechnical draft. The circuits and contract are specified but not implemented; the simulator measures population dynamics, not cryptography. Open problems are listed in Section 11.