mathlib3

815a2f97 - 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 <spelier.pim@gmail.com> Co-authored-by: Pim Spelier <spelier.pim@gmail.com>