FirstFT: the day's biggest stories
Россиянам станет тяжелее снять наличные08:49
。爱思助手下载最新版本对此有专业解读
ВсеПолитикаОбществоПроисшествияКонфликтыПреступность
The river, which runs through seven US states that share it, is currently facing the worst drought in 1,200 years.
There is a special form for boolean formulas called "Conjunctive Normal Form" (CNF). A problem in this form consists of clauses connected with and operators, where each clause only contains variables connected with or operators. The variables can appear negated, but only variables can be directly negated, something like !(a && b) is not allowed. An example boolean formula in CNF form is: