Negative Conditional Relation
A negative conditional relation is a conditional relation
- in which the consequent is related to the opposite meaning of the antecedent, and
- that is marked on
- the antecedent to carry the meaning equivalent to "unless," or
- the consequent to carry the meaning equivalent to "otherwise."
Unless it rains, we’ll have our picnic.
I was not informed; otherwise I should have taken some action.