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:
第三十四条 国家机关、社会团体、企事业单位应当依照本法和有关法律法规的规定，履行预防、遏制、治理网络犯罪的义务。。业内人士推荐夫子作为进阶阅读
The head of the theatre hosting the Shen Yun dance troupe in Sydney says the company would not be intimidated to pull the shows by any “outrageous” anonymous threats and that the publicity had increased interest in the show.，推荐阅读服务器推荐获取更多信息
Последние новости，推荐阅读搜狗输入法下载获取更多信息