Sharp optimality of 11/6 for literal ladder constructions

We prove a sharp obstruction for the literal two-row ladder family in the three-slope sums–differences construction framework. With labels (1,0), (0,1) and (1,1), every complete ladder of arbitrary length, with m edges, r initial disclosures and t initially known vertices, satisfies 6(m+r) ≥ 11(2b−t), where b is the number of positions. A six-vertex construction attains equality. The proof reduces a smallest counterexample to a rigid sequence of local events, uses forcing dependencies to bound stretches of regular projective transitions, and transfers the resulting obstruction to characteristic 11. An exact max-plus computation on 108,160 states certifies the necessary gain bound for all lengths. The accompanying standalone code reproduces the finite certificates. Thus lengthening and relabelling a literal ladder cannot improve the Katz–Tao exponent 11/6.