From groups, rings and integer divisibility to the RSA cryptosystem and Pratt calculus for proving primes.
Polynomially decidable (computable) problems and functions, the class NP.
A course intended for students who said goodbye to mathematics some time before continuing to higher education, but did not take a negative attitude towards it. No preliminary knowledge is assumed, the progress will be slow or moderate, but the mathematics will be real, with proofs and abstract thinking.