• Further closure properties of input-driven pushdown automata 

      Okhotin, Alexander; Salomaa, Kai (Elsevier, 2019-05-20)
      The paper investigates the closure of the language family defined by input-driven pushdown automata (IDPDA) under the following operations: insertion ins(L,K)={xyz|xz∈L,y∈K}, deletion del(L,K)={xz|xyz∈L,y∈K}, square root ...