bold symbols, but the add-on AMS Fonts package (amsfonts) by the American Mathematical Society provides this facility for uppercase letters (e.g., is written as \mathbb{R}). The amssymb package loads amsfonts. In Unicode, a few of the more common blackboard bold characters (ℂ, ℍ, ℕ, ℙ, ℚ, ℝ, and ℤ) are encoded in the Basic Multilingual Plane (BMP) in the Letterlike Symbols (2100–214F) area, named DOUBLE-STRUCK CAPITAL C etc. The rest, however, are encoded outside the BMP, in Mathematical Alphanumeric Symbols (1D400–1D7FF), specifically from U+1D538 to U+1D550 (uppercase, excluding those encoded in the BMP), U+1D552 to U+1D56B (lowercase) and U+1D7D8 to U+1D7E1 (digits). Usage The following table shows all available Unicode blackboard bold characters. The first column shows the letter as typically rendered by the LaTeX markup system. The second column shows the Unicode code point. The third column shows the Unicode symbol itself (which will only display correctly on browsers that support Unicode and have access to a suitable font). The fourth column describes some typical usage in mathematical texts. Some of the symbols (particularly and ) are nearly universal in their interpretation, while others are more varied in use. In addition, a blackboard-bold μn (not found in Unicode) is sometimes used by number theorists and algebraic geometers to designate the group scheme of nth roots of unity. LaTeX notes: Only uppercase letters are given LaTeX renderings because is used here. Italicized blackboard bold is not rendered in LaTeX here due to the complexity involved. See also Mathematical alphanumeric symbols Set notation References Bibliography External links Mathematical notation Mathematical typefaces