You may recall in last week's extra credit, we showed that if you give a PDA 2 stacks instead of 1, it's able to accept the language a^nb^nc^n that no normal PDA could accept. This week, we'll show an even stronger result. Show how any Turing machine can be converted to an equivalent 2-stack PDA. (This proves that the set of languages 2-stack PDAs can be built to accept is exactly the set of decidable languages)