F# lab

 //task2 lab1
   (*
    let list  = [
       for i in 1 .. 10 do
        yield (1+i)*i/2-i+1
    ]
    printf "%A" list
     *)

    //task1 lab2
    (*
    let list123 = [ 1; 2; 3;4 ]
    let rec printList listx max   =
        match listx with
            | head :: tail -> if head%2=0&&max<head then printList tail head
                                   else printList  tail max
            | [] -> max
    let ans = printList  list123 -1
    printf "%A" ans
   *)


    //task2 lab2
    (*
    let list  = List.rev [0; 1;2;1; 0 ]
    //printf "%A" list
    let checkPalindrom list listRev = List.fold2 (fun acc elem1 elem2 -> if (elem1 <> elem2) then false else acc ) true list listRev
    let ans = checkPalindrom list (List.rev list)
    printf "%A" ans
   *)


    //task3 lab2
    (*
    let s = seq { 2; 5; 4; 7; 11; 16}
   // let s = seq { 2; 5; 8; 11; 14; 17}
    let seqWindows = Seq.windowed 2 s
    let seqSubtract = Seq.map (fun elem->(Array.get elem 1) - (Array.get elem 0)) seqWindows
    let d = Seq.head seqSubtract
    let f = Seq.fold (fun acc elem -> if (Seq.head seqSubtract <> elem) then false else acc ) true  seqSubtract
    let a1 = Seq.head s

    if f then printf "Это арифмитическая прогрессия  . а1= %A  ,d = %A " a1 d
    else printf "Не арифмитическая прогрессия ."
    *)