Pi
(Built-in Mathematica Symbol) Pi is \[Pi], with numerical value \[TildeEqual] 3.14159.
PolynomialRemainder[p, q, x] gives the remainder from dividing p by q, treated as polynomials in x.
Positive[x] gives True if x is a positive number.
PrecedesEqual[x, y, ...] displays as x \[PrecedesEqual] y \[PrecedesEqual] ....
Precedes[x, y, ...] displays as x \[Precedes] y \[Precedes] ....
PrecedesSlantEqual[x, y, ...] displays as x \[PrecedesSlantEqual] y \[PrecedesSlantEqual] ....
PrecedesTilde[x, y, ...] displays as x \[PrecedesTilde] y \[PrecedesTilde] ....
PreserveImageOptions is an option to graphics and related functions that specifies whether image size and certain other options should be preserved from the previous version ...
Proportional[x, y, ...] displays as x \[Proportional] y \[Proportional] ....
Proportion[x, y, ...] displays as x \[Proportion] y \[Proportion] ....