A problem used as an example in complexity theory. It can be stATed thus: Given a Boolean expression E, decide if there is some assignment to the variables in E such thAT E is true. A Boolean expression is composed of Boolean variables, (logical) negATion (NOT), (logical) conjunction (AND) and parentheses for grouping. The sATisfiability problem was the first problem to be proved to be NP-complete (by Cook). ["Introduction to AutomATa Theory, Languages, and ComputATion" by Hopcroft and Ullman, pub. Addison-Wesley]. (1994-11-11)