Math symbols can stretch the boundaries of Unicode display technology, but not as much as some other related blocks like Letterlike Symbols the home of such symbols as ℙ (double struck P, see image below), ℚ (double struck Q), and even the pharmacy prescription symbol (℞).
Double struck letters in particular are used in different branches of mathematics to respresent, for instance, the set of all real numbers (double struck R) or in symbolic logic to symbolize any atomic proposition. See the table below for different double struck letters and their Unicode values. See the Penn State Math Symbol chart for other common letter like symbols of math.
|DOUBLE-STRUCK REAL NUMBER (Double R)||ℝ||—||ℝ||ℝ|
|COMPLEX NUMBERS (Double C)||ℂ||—||ℂ||ℂ|
|NATURAL NUMBERS (Double N)||ℕ||—||ℕ||ℕ|
|PRIME NUMBERS (Double P)||ℙ||—||ℙ||ℙ|
|RATIONAL NUMBERS (Double Q)||ℚ||—||ℚ||ℚ|
|INTEGERS (Double Z)||ℤ||—||ℤ||ℤ|