TURKISH JOURNAL OF MATHEMATICS, sa.2, ss.291-295, 2012 (SCI-Expanded)
We prove that if a non-zero weakly compact-friendly operator B on a Banach lattice with topologically full center is locally quasi-nilpotent, then the super right-commutant [B > of B has a non-trivial closed invariant ideal. An example of a weakly compact-friendly operator which is not compact-friendly is also provided.