  This article investigates a class of discrete nabla fractional operators by
using the discrete nabla convolution theorem. Inspired by this, we define the
discrete generalized nabla fractional sum and differences of Riemann-Liouville
and Caputo types. In the process, we give a relationship between the
generalized discrete delta fractional operators introduced by Ferreira
\cite{Ferreira} and the proposed discrete generalized nabla fractional
operators via the dual identities. Also, we present some test examples to
justify the relationship. Moreover, we prove the fundamental theorem of
calculus for the defined discrete generalized nabla fractional operators.
Inspired by the above operators, we define discrete generalized nabla
Atangana-Baleanu-like (or Caputo-Fabrizio-like) fractional sum and differences
at the end of the article.
