Shades of orange sometimes misspelled as "vermillion". Also known as "cinnabar" and in its deeper form known as "China red", vermilion is reddish orange, much like scarlet, only more orange than scarlet. It can be produced naturally (from the mineral cinnabar) and artificially. Cinnabar is a deep red-orange mineral, mercuric sulfide, HgS; the principal ore of mercury; the pigment vermilion is extracted from this ore. The web color "tomato" is a medium reddish-orange color that is the color of actual supermarket tomatoes. Many vine-ripened tomatoes are a bit redder. The color of tomato soup is slightly less saturated. The color "tomato" is displayed
Ore extension which means that "δ" is a homomorphism of abelian groups satisfying Then the Ore extension "R"["x";"σ","δ"], also called a skew polynomial ring, is the noncommutative ring obtained by giving the ring of polynomials "R"["x"] a new multiplication, subject to the identity If "δ" = 0 (i.e., is the zero map) then the Ore extension is denoted "R"["x"; "σ"]. If "σ" = 1 (i.e., the identity map) then the Ore extension is denoted "R"["x","δ"] and is called a differential polynomial ring. The Weyl algebras are Ore extensions, with "R" any commutative polynomial ring, "σ" the identity ring endomorphism, and "δ" the