Arithmetic and Number Theory in C -- Number Formats: The Representation of Large Numbers in C -- Interface Semantics -- The Fundamental Operations -- Modular Arithmetic: Calculating with Residue Classes -- Where All Roads Meet: Modular Exponentiation -- Bitwise and Logical Functions -- Input, Output, Assignment, Conversion -- Dynamic Registers -- Basic Number-Theoretic Functions -- Rijndael: A Successor -- Large Random Numbers -- Strategies for Testing LINT -- Arithmetic in C++ with the Class LINT -- Let C++ Simplify Your Life -- The LINT Public Interface: Members and Friends -- Error Handling -- An Application Example: The RSA Cryptosystem -- Do It Yourself: Test LINT -- Approaches for Further Extensions.