Image-Wall Pullback Divisors

This note separates cleared ambient pullback divisors from ALA_LAL-chart restricted pullback divisors for two image-side walls of endpoint-compression word fibers. It proves that the determinant-zero and endpoint-wall pullbacks are principal, squarefree, reduced, and have no embedded components on the relevant chart, with the endpoint wall retaining a terminal factor and a continuant-residue factor after the head factor becomes a unit.