University of Sistan and BaluchestanIranian Journal of Fuzzy Systems1735-065413220160430Alternating Regular Tree Grammars in the Framework of Lattice-Valued Logic7194236010.22111/ijfs.2016.2360ENMaryamGhoraniFaculty of Mathematical Sciences, Shahrood University of Technology, Shahrood, IranMohammad MehdiZahediDepartment of Mathematics, Graduate University of Advanced Technology, Kerman, Iran0000-0003-3197-9904Journal Article20140817In this paper, two different ways of introducing alternation for lattice-valued (referred to as {L}valued) regular tree grammars and {L}valued top-down tree automata are compared. One is the way which defines the alternating regular tree grammar, i.e., alternation is governed by the non-terminals of the grammar and the other is the way which combines state with alternation. The first way is taken over to prove a main theorem: the class of languages generated by an {L}valued alternating regular tree grammar {LAG}) is equal to the class of languages accepted by an {L}valued alternating top-down tree automaton {LAA}). The second way is taken over to define a new type of automaton<br /> by combining the {L}valued alternating top-down tree automaton with stack, called {L}-valued alternating stack tree automaton {LASA} and the generative power of it is compared to some well-known language classes, especially to {LAA} and to {LAG}<br />Also, we have derived a characterization of the state alternating regular tree grammar {LSAG}) in terms of {LASA}.https://ijfs.usb.ac.ir/article_2360_9a374f39abaa600423ce805945586dd1.pdf