let rec iter f i a b =
    if a<=b then
        f (iter f i (a+1.) b) a
    else i

let sum a b = iter (+) 0. a b


let fact n = iter (*) 1. 1. n




sum 1. 2.

fact 5.

//stepen
let rec f1 x n =
    if n>0. then
        x * (f1 x (n-1.))
    else 1.


//1 член послед втупом методе
let f2 x n = (f1 x (2. * n)) / (fact n)



//DUMB
let rec tylerSum x n=
    if ((f2 x n) = (f2 x (n+1.))) then (f2 x n)
    else
        (+) (f2 x n) (tylerSum x (n+1.))

tylerSum 0.2 0.


let rec myfor a b=
    if a<b then
        printfn("%f %f") a (tylerSum a 0.)
        myfor (a+0.1) b

myfor 0. 1.

//smart
let rec tylerSum2 x n NUM=
    let F1=(float)NUM*x*x/n
    if (NUM = F1) then NUM
    else
        (+) NUM (tylerSum2 x (n+1.) F1)

//tylerSum2 0.1 1. 1.


open System
open System.Numerics




//function!!!!!!!!!!!!!!

let func111 x = Math.Pow ( Math.E , x*x )


func111 0.1





let rec myfor2 a b=
    if a<b then
        printfn("%f  %f  %f  %f") a (tylerSum a 0.) (tylerSum2 a 1. 1.) (func111 a)
        myfor2 (a+0.1) b

myfor2 0. 1.


/////////////////////////////////////////////////////


let FUNC x= Math.Cos(x/2.) - 2.* Math.Sin(1./x) + 1./x

FUNC 1.8756


let rec solve a b =
    let avg=(a+b)/2.
    let znach=FUNC avg
    if (b-a)<0.000001 then printfn("%f") avg
    else
        if znach>0. then (solve avg b)
        else
            if znach<0. then (solve a avg)

let koren=solve 1. 2.

let proizv x=(2.*Math.Sin(2./x)+2.*Math.Cos(1./x)-1.)/x/x

proizv 2.

let rec solve1 a b x0=
    let x1=x0-((FUNC x0)/(proizv x0))
    if Math.Abs(x0-x1)<0.001 or x1>b or x1<a then printfn("%f") x0
    else solve1 a b x1


solve1 1. 2. 2.
/////метод итераций
let min=proizv 2.
let max=proizv 1.
let c = 2. /(min + max)


let rec solve3 a b x0=
    let x1=x0-c*(FUNC x0)
    if Math.Abs(x0-x1)<0.001 or x1>b or x1<a then printfn("%f") x1
    else solve3 a b x1

solve3 1. 2. 2.

////////////////////////////////////////////////////////SEMMINAR


open System
open System.IO


let s=File.ReadAllLines("D:\\FSharpCodingDojo-master\\FSharpCodingDojo-master\\DigitRecognizer\\validationsample.csv")

let m=(s |> Array.map(fun x-> x.Split(','))).[1] |> Array.map(int)

//for i in 1 .. s.Length-1 do
//    let SS=s.[i].Split(',') |> Array.map(int)



let a=[1;2;3;4]

let b =[5;6;7;8]


 //[1;2;3;4]@[5;6;7;8]

 let rec append L M=
    match L with
    |[]-> M
    |h::t->h::(append t M)

let c = append a b


let print X=
    List.iter(printf "%A ") X

print c

let d = List.filter(fun x -> x%2=0) c

List.map(fun x -> x*2) d

let gen n=
    let mutable x=n
    fun()->
        x <- x+1
        x

let a = Seq.unfold (fun(u,v) -> Some (u,(v,v+u))) (1,1)

//////////////////////

seq{1..100}

let ss=(Seq.append [1;2;4] [2;3;4;5]) |> List.map(fun x->x*2)


//////////////////////////
type formatText=
    | Str of string
    | Bullet_item of List<formatText>
    | Bold_text of formatText
    | Italic_text of formatText
    | Headers of formatText


let rec render formatText =
    match formatText with