interposing

Interposing is the act of placing something between two other things, or introducing an intervening agent or action. It is a general concept that appears across many domains, as well as a number of formal doctrines or tactics.

In law and politics, interposition refers to a historical doctrine by which a state claimed the right to oppose federal authority by interposing its power. It arose in debates over federal supremacy and states’ rights and is controversial. Modern courts have generally rejected the idea that states may unilaterally block federal laws.

In chess, interposing is a defensive tactic to block a line of attack by placing a piece on the line between the opponent’s attacker and the king. It is only legal when the line of attack can be interrupted, as in blocking a check from a sliding piece.

In perception and art, interposition is a depth cue in which nearer objects partially obscure farther ones, helping to convey three-dimensional space. In film and photography, interposed elements or overlay techniques can create layering or compositional depth.

In engineering and technology, an interposer is a component placed between two elements to provide electrical contact, mechanical alignment, or signal conditioning, and interposing devices can adapt interfaces or manage propagation.