tolni'i lujvo

x1 (event/state) logically necessitates/entails/implies the negation of x2 (event/state), under rules/logic system x3. x1 prevents x2.

to'e nibli. “lo nu broda cu tolni'i lo nu brode” has the same meaning as “lo nu broda cu nibli lo nu na brode”.

In definition:

na'e tolni'i modal, first place; despite the logically sufficient condition...