excess³: a pre-specified continuous proxy for order-3 synergistic surplus — methods, Spanish introduction, and cross-disciplinary guide

excess³ (excess3 in software) is a pre-specified continuous proxy for order-3 synergistic surplus in the Systemic Tau / RECD programme. This deposit archives the shared document family: methods/ — canonical English methods paper: formal definition, null models (phase-shuffle on the full contrast), synthetic validation arms G0–G3, reporting checklist. intro/ — dense Spanish introduction with integrated validation figures and results-writing guidance. primer/ — English cross-disciplinary pedagogical guide (analogies, domain vignettes, teaching notes). Contract (short): excess3 = 0.6·Syn + 0.4·Surp with weights fixed a priori; continuous primary / Φ₃ secondary; inference on full |Δ|; proxy ≠ full PID; parallel RECD nesting; dependence language, not causation. GitHub: https://github.com/johelpadilla/excess3 Cite the methods PDF for the statistical specification.