contingency

n. 偶然(列联,意外费用,相切)

The classification of propositions on the basis of whether they assert or deny the possibility, impossibility, contingency, or necessity of their content.

模态逻辑命题的限制条件，建立在其内容的肯定或否定其可能性，不可能性，偶然性或必然性基础之上

It's impossible to legislate for every contingency.

为每一偶发事件都立法是不可能的.