On Wed, Oct 28, 2015 at 5:52 PM,
but if I write: [(x,y)|x<-[1..5],y<-[1..5],x<-[1]] I obtain:
[(1,1),(1,2),(1,3),(1,4),(1,5),(1,1),(1,2),(1,3),(1,4),(1,5),(1,1),(1,2),(1,3),(1,4),(1,5),(1,1),(1,2),(1,3),(1,4),(1,5),(1,1),(1,2),(1,3),(1,4),(1,5)]
Others will chime in with a full answer soon. Meanwhile, consider that [(x,y)|x<-[1..5],y<-[1..5],x<-[1]] (which is quite weird as a set-theoretic expression) is Haskell-equivalent to [(x,y)|_<-[1..5],y<-[1..5],x<-[1]] Now consider [(x,y)|y<-[1..5],x<-[1]] which is [(1,1),(1,2),(1,3),(1,4),(1,5)] as you expect. Separately, consider [ a | _ <- [1..5], f a ] where you can experiment with different values of f and a. Putting together the pieces will give you an answer to your query. -- Kim-Ee