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:
-seen_urls: set，详情可参考同城约会
而中低端产品及欧美地区的销售，则全面委托给创维、TCL 等中国企业操刀。，这一点在heLLoword翻译官方下载中也有详细论述
The radio silence that accompanies re-entry went on far longer than normal. Millions watched on TV, many convinced that all was lost.，更多细节参见搜狗输入法2026