  Sequent-type proof systems constitute an important and widely-used class of
calculi well-suited for analysing proof search. In my master's thesis, I
introduce sequent-type calculi for a variant of default logic employing
\Lukasiewicz's three-valued logic as the underlying base logic. This version of
default logic has been introduced by Radzikowska addressing some
representational shortcomings of standard default logic. More specifically, the
calculi discussed in my thesis axiomatise brave and skeptical reasoning for
this version of default logic, respectively following the sequent method first
introduced in the context of nonmonotonic reasoning by Bonatti and Olivetti,
which employ a complementary calculus for axiomatising invalid formulas, taking
care of expressing the consistency condition of defaults.
