The
inverse is a type of
conditional sentence in formal logic. Any conditional sentence has an inverse: the
contrapositive of the
converse. The inverse of

is thus

. For example, substituting propositions in natural language for logical variables, the inverse of the conditional proposition "If it's raining, then Sam will meet Jack at the movies." is "If it's not raining, then Sam will not meet Jack at the movies.".
The inverse of the inverse, that is, the inverse of

, is

. Since a double negation has no logical effect, the inverse of the inverse is logically equivalent to the original conditional

. Thus it is permissible to say that

and

are inverses of each other. Likewise, we may say that

and

are inverses of each other.
The inverse and the converse of a conditional are logically equivalent to each other, just as the conditional and its contrapositive are logically equivalent to each other. But the inverse of a conditional is not inferable from the conditional. For example, "If it's not raining, then Sam will not meet Jack at the movies." cannot be inferred from "If it's raining, then Sam will meet Jack at the movies.". It could easily be the case that Sam and Jack are attending the movies no matter the weather.