package preface

Expressing a value of this type is impossible.

The law according to which any statement can be proven from a contradiction. That is, once a contradiction has been asserted, any proposition (including their negations) can be inferred from it; this is known as deductive explosion.

If there is void on the right part of Either, we know that the Either is in Left branch.

If there is void on the left part of Either, we know that the Either is in Right branch.