View source for Combining random variables

[[Random variable]]s are neither "random" nor "variable".  However, by defining arithmetic operations on them, we can put them into equations, where they can act like variables.

{{:+ (random variables)}}

Similarly, we can define other operations:

{{:· (random variables)}}

{{:- (random variable)}}

{{:Example:area of rectangle as a random variable}}

Because we define operations on [[random variable]]s [[pointwise]], random variables behave the same way as [[real number]]s do.  For example,

{{:Proof:Random variables satisfy distributivity}}