  The rigorous theoretical analyses of algorithms for exact 3-satisfiability
(X3SAT) have been proposed in the literature. As we know, previous algorithms
for solving X3SAT have been analyzed only regarding the number of variables as
the parameter. However, the time complexity for solving X3SAT instances depends
not only on the number of variables, but also on the number of clauses.
Therefore, it is significant to exploit the time complexity from the other
point of view, i.e. the number of clauses. In this paper, we present algorithms
for solving X3SAT with rigorous complexity analyses using the number of clauses
as the parameter. By analyzing the algorithms, we obtain the new worst-case
upper bounds O(1.15855m), where m is the number of clauses.
