This morning I had a fun support request related to our software. The exchange took place over email but it could have fit into a couple Twitter messages. Would that all requests could be answered so succinctly.
Do you have R code to compute P(X > Y) where X ~ gamma(ax, bx) and Y ~ gamma(ay, by)?
ineq <- function(ax, bx, ay, by) pbeta(bx/(bx+by), ay, ax)
For more on the problem and the solution, see Exact calculation of inequality probabilities.