This problem is also known as "Boolean or propositional satisfiability". Computer scientists usually call it SAT. Complexity theory believes that the formula should be in a special form, known as conjunctive normal form. A formula that is in this form has clauses. Clauses are joined by a "logical and". Each clause has several literals. They are joined by a "logical or". A literal and its complement cannot appear in the same clause. The problem may also have other names. The names depend on what the logical formula looks like. The names also depend on how many variables are used per clause.