SS120 CONT. - The MPSR Logic‑Gate: Gridlock Conditions on the SS120 Compliance Highway (Meta‑Level to SS120 Corollaries)

We define a four‑input institutional control gate— MPSR—with inputs derived from the SS120 checkpoints: M (parity/no disparate treatment), P (process lean—no procedural flooding), S (lawful routing—no defensive isolation/faculty‑shielding), and R (minimum viable reform engaged). We specify a transfer function mapping ({0,1}^4) to four macrostates—PASS (free flow), SLOW (constrained flow), GRIDLOCK (no internal progress), and EXIT (externalization to press/regulators/courts). We prove monotonicity and tipping properties, provide a reduced truth table, define observables that operationalize each input, and show how R functions as an override that clears gridlock. The gate formalizes when the SS120 highway carries cases forward and when institutional control collapses into scandal unless reform is deployed. Keywords: recursion capture, student advocacy, control gate, SS120, compliance engineering, gridlock conditions, compliance highway