A combinational ternary logic gate that is important as a building block in the synthesis of ternary logic circuits (see multivalued logic). A T-gate has four inputs

and one output {t}, all of which can take values represented by elements of the set {0,1,2}. The function of the T-gate is given by t = a_s. It thus acts as a ternary selector, the choice frombeing selected by the value taken by the s input.