feat(computability/encoding): define encoding of basic data types (#3976)
feat(computability/encoding): define encoding of basic data types (#3976)

We define the encoding of natural numbers and booleans to strings for Turing machines to be used in our future PR on polynomial time computation on Turing machines.



Co-authored-by: Pim <5e4eaba5b6f77f500965c15b0f4f048887acfd6f@gmail.com>
Co-authored-by: Pim Spelier <5e4eaba5b6f77f500965c15b0f4f048887acfd6f@gmail.com>

leanprover-community/mathlib,leanprover-community/mathlib