Hello, monax, you wrote: M> Haskel another absolutely. How much I understood, lazy calculations in puzzle to people because to force it to create side-effect difficult. However, it while only on responses, it was not possible to study it yet. Ghost effects in form easily. Simply they should be registered explicitly through types, and it is unusual for many. M>F# is, consider, OCaml. Only they added there null and connected with.net. Like as people get accustomed and even use, but for me there is a big lack - MS. I.e. under I in any way will not get it ( it is not counted, this strange thing), and under I just and work. So for passage on F# there should be something not ordinary that I spat all knowledge in a linuh-ecosystem and passed in . Here or me it will be necessary to carry out the task which here 100 % well lay down on +, but does not lay down at all on +, or F# should offer to me such wild advantages that without it in any way. But it will not be, and is "with a view of erudition increase", on it did not gather to drag yet. F# as language is pleasant to me even more than Ocaml. Especially in the first are pleasant sequence expressions and its generalization computations expressions. But too the knot on fat afflicts.