ternäre

Ternäre is the German adjective meaning three-part or ternary. It is used in technical vocabularies to describe systems, relations, or operations that involve three components. The term derives from Latin ternarius, from terni "three apiece," and is cognate with related terms in other European languages. In English-language contexts, "ternary" is used with a similar meaning, for example in ternary systems, ternary logic, or ternary operators.

In mathematics and logic, a ternary operation is a function of three arguments, and a ternary relation involves three elements. Ternary logic extends classical two-valued logic to accommodate a third truth value, with historical systems such as Lukasiewicz three-valued logic and Kleene's three-valued logic influencing programming language design and artificial intelligence research.

In computing, "ternary" often refers to base-3 numeral systems and trinary digits (trits). The historically notable Setun computer used ternary arithmetic, and balanced ternary—using digits −1, 0, and 1—offers symmetric representation around zero. Most contemporary hardware uses binary, but research into ternary computing explores potential gains in information density and fault tolerance, as well as novel circuit and memory technologies.

In chemistry and materials science, ternary denotes systems composed of three components. Ternary phase diagrams map the phase behavior of three-component mixtures, and ternary alloys or compounds arise from three constituent elements. These concepts aid the study of eutectic points, peritectic reactions, and the thermodynamics of complex materials.