Pr

Symbol

 * 1)  praseodymium.
 * 2)  probability
 * $$\mathrm{Pr}(B|A) = \frac {\mathrm{Pr}(A|B) \cdot \mathrm{Pr}(B)} {\mathrm{Pr}(A)}$$
 * 1) Prandtl number

Usage notes
Arguably should not be used, because of confusion with Pr = praseodymium.