1Department of Mathematics, Iaypee Institute of Information Technology University, A-lO, Sector-62, Noida (Uttar Pradesh), India-20l307, E-mail: alka.choubey@jiit.ac.in, alka_ch@hotmail.com
2Department of Mathematics, ISS Academy of Technical Education, C-2O/l, Sector 62, Noida (Uttar Pradesh), India-20l30l, E-mail: rv_km@yahoo.com
Vague sets are an extension of fuzzy sets, each object of which has a grade of membership whose value is a continuous subinterval of [0, 1]. In this paper, using the concept of vague sets a definition of vague regular language is proposed and their related properties are studied. A finite automaton (DFA and NDFA) model with vague transitions and vague (final) states are proposed. The acceptance of vague regular language through these models is discussed. It is observed that, the finite automaton (DFA and NDFA) model with vague (final) states is more suitable for recognizing vague regular language than the finite automaton (DFA and NDFA) model with vague transitions. In the end, vague regular expressions are introduced. The proposed vague regular expressions can be used in lexical analysis.
Vague language, vague regular language, finite automaton with vague transitions, finite automaton with vague (final) states, vague regular expression
