03E75 20F99 2 20K99 2 partition of a group 2 03E05 1 06A11 1 20K20 1 20K30; 13C99 1 54A05,54E15 1 Black Box 1 \(E(R)\)-algebra 1 \(E\)-ring 1 asymorphism 1 ballean 1 endomorphism algebra 1 irresolvable ballean 1 k-thin subsets of a group 1 prediction principle 1 pseudobounded ballean 1 pseudodiscrete ballean 1 quasiasymorphism 1 slowly oscillating function 1 sparse subset of a group 1 ultra-cotorsion-free module 1