When an implementation under test (IUT) is state-based, and its expected abstract behavior
is given in terms of a finite state machine (FSM), a checking sequence generated from a
specification FSM and applied to an IUT for testing can provide us with high-level confidence
in the correct functional behavior of our implementation. One of the issues here is to
generate efficient checking sequences in terms of their lengths. As a major characteristics, a
checking sequence must contain all β-sequences for transition verification. In this paper, we�…

Duan and Chen (doi: 10.1016/j. jss. 2009.05. 019) proposed two methods for constructing
an input/output sequence (IOS) whose execution on an implementation N of a given
deterministic finite state machine (DFSM) M tests that N can be interpreted as a DFSM
properly implementing every individual state and transition of M. This paper shows that the
methods and three earlier similar methods potentially introduce cyclic dependencies
between the essential segments of the produced IOS, meaning that the IOS might fail to be a�…