Is this a typo in Ct6-04 (reinsurance)?

on page 6

We are told that E(Y) = (integral of blah) dx + M Pr (X > M)

What is Pr(X>M)? I have never come across this notation before. Nor have I seen it in the notes. (I will be highly embarrassed if it was in the notes after all! )

thanks in advance

 

Probability that X (random Variable) is greater than M (constant)

It comes from the remainder when you subtract the first integral as given from the integral over everything (which gives the mean)

 

Thanks!

in that case,
I would've thought the notation would be:
P(X>M)

Oh well!