Duplication is an operation generating a language from a single word by iterated application of rewriting rules u uu on factors. We extend this operation to entire languages and i...
Masami Ito, Peter Leupold, Kayoko Shikishima-Tsuji
Recently the duplication closure of words and languages has received much interest. We investigate a reversal of it: the duplication root reduces a word to a square-free one. After...
Abstract. We prove that the class of context-free languages with polynomially bounded ambiguity (PCFL) is the closure of the class of unambiguous languages (UCFL) under projections...
Duplication is the replacement of a factor w within a word by ww. This operation can be used iteratively to generate languages starting from words or sets of words. By undoing dupl...
In this work we generalize the fundamental notion of recognizability from untimed to timed languages. The essence of our definition is the existence of a right-morphism from the m...