anchor.diff:  module SHA1 = 
       let inline (>>>&)  (x:int) (y:int)  = int32 (uint32 x >>> y)
       let f(t,b,c,d) = 
  -        if t < 20 then (b &&& c) ||| ((~~~b) &&& d) else
  -        if t < 40 then b ^^^ c ^^^ d else
  -        if t < 60 then (b &&& c) ||| (b &&& d) ||| (c &&& d) else
  -        b ^^^ c ^^^ d
  -
  -    let k0to19 = 0x5A827999
  -    let k20to39 = 0x6ED9EBA1
  -    let k40to59 = 0x8F1BBCDC
  -    let k60to79 = 0xCA62C1D6
  +        if t < 20 then (b &&& c) ||| ((~~~b) &&& d)
  +        elif t < 40 then b ^^^ c ^^^ d
  +        elif t < 60 then (b &&& c) ||| (b &&& d) ||| (c &&& d)
  +        else b ^^^ c ^^^ d
  +
  +    let [<Literal>] k0to19 = 0x5A827999
  +    let [<Literal>] k20to39 = 0x6ED9EBA1
  +    let [<Literal>] k40to59 = 0x8F1BBCDC
  +    let [<Literal>] k60to79 = 0xCA62C1D6
   
       let k t = 
           if t < 20 then k0to19 
  
positive.code:         let res = (b0 <<< 24) ||| (b1 <<< 16) ||| (b2 <<< 8) ||| b3
          res
  
  
      let sha1_hash sha = 
          let h0 = ref 0x67452301
          let h1 = ref 0xEFCDAB89
          let h2 = ref 0x98BADCFE
          let h3 = ref 0x10325476
          let h4 = ref 0xC3D2E1F0
          let a = ref 0
          let b = ref 0
          let c = ref 0
          let d = ref 0
          let e = ref 0
          let w = Array.create 80 0x00
          while (not (sha_eof sha)) do
            for i = 0 to 15 do
              w.[i] <- sha_read32 sha
            for t = 16 to 79 do
              w.[t] <- rot_left32 (w.[t-3] ^^^ w.[t-8] ^^^ w.[t-14] ^^^ w.[t-16]) 1;
            a := !h0; 
            b := !h1; 
            c := !h2; 
            d := !h3; 
            e := !h4;
            for t = 0 to 79 do
              let temp =  (rot_left32 !a 5) + f(t,!b,!c,!d) + !e + w.[t] + k(t)
              e := !d; 
              d := !c; 
              c :=  rot_left32 !b 30; 
              b := !a; 
              a := temp;
            h0 := !h0 + !a; 
            h1 := !h1 + !b; 
            h2 := !h2 + !c;  
            h3 := !h3 + !d; 
            h4 := !h4 + !e
          done;
          (!h0,!h1,!h2,!h3,!h4)
  
      let sha1HashBytes s = 
          let (_h0,_h1,_h2,h3,h4) = sha1_hash { stream = SHABytes s; pos = 0; eof = false }   // the result of the SHA algorithm is stored in registers 3 and 4
  
negative.code: 
      let rot_left32 x n =  (x <<< n) ||| (x >>>& (32-n))
  
      let inline sha_eof sha = sha.eof
  
      (* padding and length (in bits!) recorded at end *)
      let sha_after_eof sha  = 
  