Factors and Subwords of Rich Partial Words.

Many classes of finite words have noticeable properties with reference to their palindromic factors and one among them are the words having zero palindromic defect i.e., words rich in palindromes. In this paper we introduce rich partial word and discuss its combinatorial properties. We show that the palindromic richness of a partial word can be studied by including the positions of the missing symbols in that word. The significant difference between rich and rich partial word is that a rich word of length n contains exactly n + 1 distinct palindromic factors whereas a rich partial word of length n contains at least n + 1 distinct palindromic factors. These factors differ from the classical palindromes due to the presence of holes. [ABSTRACT FROM AUTHOR]