The DM74LS181 is a 4-bit Arithmetic Logic Unit (ALU) which can perform all the possible 16 logic operations on two variables and a variety of arethmetic operations.
Features
Provides 16 arithmetic operations: add, subtract, compare, double, plus twelve other arithmetic operations
Provides all 16 logic operations of two variables: exclusive-OR, compare, AND, NAND, OR, NOR, plus ten other logic operations
Full lookahead for high speed arithmetic operation on long words