EPDA
Embedded Push-Down Automata (EPDA) were defined in (Vijay-Shanker, 1988) as an exten- sion of Push-Down Automata that accept exactly the class of Tree Adjoining Languages.
An EPDA consists of a finite state control, an input tape and a stack made up of non-empty stacks containing stack symbols. A transition can consult the state, the input string and the top element of the top stack and then change the state, read a character of the input string and replace the top element by a finite sequence of stack elements to give a new top stack, and new stacks can be placed above and below the top stack.