Structure of Weakly Invertible Semi-Input-Memory Finite Automata with Delay 2

Semi-input-memory finite automata, a kind of finite automata introducedby the author of this paper for studying error propagation, are ageneralization of input-memory finite automata by appending an autonomousfinite automaton component. This paper gives a characterization onthe structure of weakly invertible semi-input-memory finite automatawith delay 2 in which input alphabets and output alphabets have twoelements and autonomous finite automata are cyclic. Forthe structure of feedforward inverse finite automata with delay 2,Zhu first gave a characterization; from a result on mutualinvertibility of finite automata, the result mentioned above alsoleads to a different characterization on the structure of feedforwardinverse finite automata with delay 2.