Embedded pushdown automaton

Imagine playing with a toy truck that has a garage on the back. The garage has many levels and each level can hold many different types of toys. Now, let's say you have a list of instructions that tell you to put certain toys in the garage and take them out in a specific order. You can follow these instructions by putting the toys in the garage and taking them out in the correct order.

An embedded pushdown automaton is like this toy truck with a garage. Instead of toys, it can hold symbols or numbers. And instead of a list of instructions, it has rules that tell it what to do with these symbols. This automaton can read these symbols, move them around in the garage, and follow the rules to change its state.

The word "embedded" means that this automaton can be included within another automaton or machine. The word "pushdown" refers to the way the symbols are pushed down or added onto a stack, which is like the levels of the toy garage. The automaton can add and remove symbols from the stack, and it can also peek at the top symbol without actually removing it.

Overall, an embedded pushdown automaton is a way of representing a set of rules that can manipulate symbols by pushing and popping them from a stack. It's like a toy truck garage, but instead of toys, it can hold symbols and it can follow specific rules to manipulate them.