Algebraic decision diagram

An algebraic decision diagram (ADD) or a multi-terminal binary decision diagram (MTBDD), is a data structure that is used to symbolically represent a Boolean function whose codomain is an arbitrary finite set S. An ADD is an extension of a reduced ordered binary decision diagram, or commonly named binary decision diagram (BDD) in the literature, which terminal nodes are not restricted to the Boolean values 0 (FALSE) and 1 (TRUE). The terminal nodes may take any value from a set of constants S. == Definition == An ADD represents a Boolean function from { 0 , 1 } n {\displaystyle \{0,1\}^{n}} to a finite set of constants S, or carrier of the algebraic structure.

Source: Wikipedia — Algebraic decision diagram (CC BY-SA 4.0)