Period 6 element heavy metal, lead is a neurotoxin that accumulates both in soft tissues and the bones. Lead poisoning has been documented from ancient Rome, ancient Greece, and ancient China. Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent other metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery white color when newly made, but often seen in air with a pink tinge owing to the surface
C-element slow environment. Note that the definition of C-element can be easily generalized for multiple-valued logic or even for continuous signals: For example, the truth table for a balanced ternary C-element with two inputs is Depending on the requirements to the switching speed and power consumption, the C-element can be realized as a coarse- or fine-grain circuit. Also, one should distinguish between single-output and differential realizations of C-element. Differential realization is possible using only NANDs (only NORs). A single-output realization is workable if and only if: There is a number of different single-output circuits of C-element built on logic gates. In