(* Content-type: application/vnd.wolfram.mathematica *)

(*** Wolfram Notebook File ***)
(* http://www.wolfram.com/nb *)

(* CreatedBy='Wolfram 15.0' *)

(*CacheID: 234*)
(* Internal cache information:
NotebookFileLineBreakTest
NotebookFileLineBreakTest
NotebookDataPosition[       154,          7]
NotebookDataLength[     21478,        554]
NotebookOptionsPosition[     17578,        479]
NotebookOutlinePosition[     19512,        523]
CellTagsIndexPosition[     19469,        520]
WindowTitle->IndexOfCoincidence
WindowFrame->Normal*)

(* Beginning of Notebook Content *)
Notebook[{
Cell[BoxData[GridBox[{
   {GridBox[{
      {
       ItemBox[Cell[BoxData[
         RowBox[{
          TemplateBox[{12},
           "Spacer1"], Cell[
          "WOLFRAM INSTITUTE/ PUZZLES SYMBOL", "PacletNameCell",
           TextAlignment->Center,ExpressionUUID->
           "2c2f3dab-8e15-4cb7-b61a-41dc8793629f"], 
          TemplateBox[{8},
           "Spacer1"]}]],
         TextAlignment->Center,ExpressionUUID->
         "b4e4395c-fd8e-4136-a963-7110c438993e"],
        Background->LightDarkSwitched[
          RGBColor[0.490196, 0.576471, 0.690196]],
        ItemSize->Full], ""}
     },
     GridBoxAlignment->{"Rows" -> {{Center}}},
     GridBoxItemSize->{"Columns" -> {Full, 
         Scaled[0.02]}, "Rows" -> {{2.5}}}], Cell[TextData[{
     Cell[BoxData[
      TagBox[
       ActionMenuBox[
        FrameBox[Cell[TextData[{
          "See Also",
          " ",
          Cell[BoxData[
           GraphicsBox[
            {GrayLevel[0.66667], Thickness[0.13], 
             LineBox[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]},
            AspectRatio->1,
            ImageSize->20,
            PlotRange->{{-3, 4}, {-1, 1}}]],ExpressionUUID->
           "22f168a3-d6f2-4beb-a87a-0c4d57a73243"]
         }],ExpressionUUID->"ac967a4c-8ac8-4b57-ac45-064a2ce24d19"],
         StripOnInput->False],{
        StyleBox[
          "\"CipherPeriods\"", "SeeAlsoRelated", StripOnInput -> False] :> 
         Documentation`HelpLookup[
          "paclet:WolframInstitute/Puzzles/ref/CipherPeriods"], 
         StyleBox[
          "\"VigenereSolve\"", "SeeAlsoRelated", StripOnInput -> False] :> 
         Documentation`HelpLookup[
          "paclet:WolframInstitute/Puzzles/ref/VigenereSolve"], 
         StyleBox[
          "\"EnglishNgramScore\"", "SeeAlsoRelated", StripOnInput -> False] :> 
         Documentation`HelpLookup[
          "paclet:WolframInstitute/Puzzles/ref/EnglishNgramScore"]},
        Appearance->None,
        MenuAppearance->Automatic,
        MenuStyle->"SeeAlso"],
       MouseAppearanceTag["LinkHand"]]],
      LineSpacing->{1.4, 0},ExpressionUUID->
      "dc6958d2-d36a-495d-bb42-f90fae1a5b25"],
     "\[ThickSpace]\[ThickSpace]\[ThickSpace]\[ThickSpace]\[ThickSpace]\
\[ThickSpace]",
     Cell[BoxData[
      TagBox[
       ActionMenuBox[
        FrameBox[Cell[TextData[{
          "Related Guides",
          " ",
          Cell[BoxData[
           GraphicsBox[
            {GrayLevel[0.66667], Thickness[0.13], 
             LineBox[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]},
            AspectRatio->1,
            ImageSize->20,
            PlotRange->{{-3, 4}, {-1, 1}}]],ExpressionUUID->
           "815ec5eb-8eb4-4577-a484-1f001b09ff86"]
         }],ExpressionUUID->"0b7e5eb2-eda0-46d5-8b04-13eabe75cb95"],
         StripOnInput->False],{
        "\"Search\"" :> 
         Documentation`HelpLookup[
          "paclet:WolframInstitute/Puzzles/guide/Search"]},
        Appearance->None,
        MenuAppearance->Automatic,
        MenuStyle->"MoreAbout"],
       MouseAppearanceTag["LinkHand"]]],
      LineSpacing->{1.4, 0},ExpressionUUID->
      "e9115a41-8a07-4ac9-8373-2833eed945a9"],
     "\[ThickSpace]\[ThickSpace]\[ThickSpace]\[ThickSpace]\[ThickSpace]\
\[ThickSpace]",
     Cell[BoxData[
      TagBox[
       ActionMenuBox[
        FrameBox[Cell[TextData[{
          "URL",
          " ",
          Cell[BoxData[
           GraphicsBox[
            {GrayLevel[0.66667], Thickness[0.13], 
             LineBox[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]},
            AspectRatio->1,
            ImageSize->20,
            PlotRange->{{-3, 4}, {-1, 1}}]],ExpressionUUID->
           "99972b11-09a7-4b53-8b55-d4e37a3b8832"]
         }],ExpressionUUID->"bc1927f8-204d-4d10-bcc5-659fda1a13aa"],
         StripOnInput->False],{
        "\"WolframInstitute/Puzzles/ref/IndexOfCoincidence\"" :> None, 
         "\"Copy Wolfram Documentation Center URL\"" :> 
         CopyToClipboard["WolframInstitute/Puzzles/ref/IndexOfCoincidence"], 
         Delimiter, "\"Copy web URL\"" :> 
         Module[{DocumentationSearch`Private`nb$}, 
           DocumentationSearch`Private`nb$ = 
            NotebookPut[
             Notebook[{
               Cell[BoxData[
                 MakeBoxes[
                  Hyperlink[
                   "http://reference.wolfram.com/language/WolframInstitute/\
Puzzles/ref/IndexOfCoincidence.html"], StandardForm]], "Input", 
                 TextClipboardType -> "PlainText"]}, Visible -> False]]; 
           SelectionMove[DocumentationSearch`Private`nb$, All, Notebook]; 
           FrontEndTokenExecute[DocumentationSearch`Private`nb$, "Copy"]; 
           NotebookClose[DocumentationSearch`Private`nb$]; Null], 
         "\"Go to web URL\"" :> 
         FrontEndExecute[{
           NotebookLocate[{
             URL[If[TrueQ[False], 
                 "http://reference.wolfram.com/system-modeler/", 
                 "http://reference.wolfram.com/language/"] <> 
               "WolframInstitute/Puzzles/ref/IndexOfCoincidence" <> ".html"], 
              None}]}]},
        Appearance->None,
        MenuAppearance->Automatic,
        MenuStyle->"URLMenu"],
       MouseAppearanceTag["LinkHand"]]],
      LineSpacing->{1.4, 0},ExpressionUUID->
      "ad6e412c-b1ff-4b12-8976-a3aac93bbb14"]
    }], "AnchorBar",
     CacheGraphics->False,ExpressionUUID->
     "6fade3ff-8d25-48d4-92c4-5556a2cea99e"]}
  }]], "AnchorBarGrid",
 CellID->1,ExpressionUUID->"8edc7082-4deb-4f5e-92c5-252dbcd0dc9c"],

Cell["WolframInstitute`Puzzles`", "ContextNameCell",ExpressionUUID->"258627a4-a553-4ac3-a8c0-7d7922e7eaa9"],

Cell[CellGroupData[{

Cell[BoxData[GridBox[{
   {Cell[TextData[{
     Cell[
     "IndexOfCoincidence", "ObjectName",ExpressionUUID->
      "97fbfab9-02a5-4531-970d-f84d0fa0a387"],
     Cell[BoxData[
      TemplateBox[{8},
       "Spacer1"]],ExpressionUUID->"08b6eca9-8479-4baf-ae24-03b53bc2730b"],
     Cell[BoxData[
     ""], "ObjectNameTranslation",ExpressionUUID->
      "636097ab-d7a6-4d06-9ea9-9768e10adb7e"]
    }],ExpressionUUID->"1156c3fe-f630-49e9-9422-25c07cc6157d"], 
    "\[SpanFromLeft]"}
  }]], "ObjectNameGrid",ExpressionUUID->"34078166-6906-49dd-9b1e-\
5d4106b8d7ab"],

Cell[BoxData[GridBox[{
   {"", Cell[TextData[{
     Cell[BoxData[
      RowBox[{
       TemplateBox[{
         Cell[
          TextData["IndexOfCoincidence"]], 
         "paclet:WolframInstitute/Puzzles/ref/IndexOfCoincidence", 
         "WolframInstitute/Puzzles Package Symbol"},
        "PackageLink",
        BaseStyle->"InlineFormula"], "[", 
       StyleBox["text", "TI"], "]"}]], "InlineFormula",
      FontFamily->"Source Sans Pro",
      FontSize->0.9 Inherited,ExpressionUUID->
      "82333208-31c5-438f-99fa-b7479d9eb4a5"],
     "\[LineSeparator]",
     "gives the index of coincidence of the letters in text: the probability \
that two letters drawn from it without replacement are equal."
    }],ExpressionUUID->"e4ec00a3-590e-4c28-8579-22cd2fecdc24"]}
  }]], "Usage",ExpressionUUID->"918c3f12-e51b-4c73-8c4e-f1073da95ccc"]
}, Open  ]],

Cell[CellGroupData[{

Cell[TextData[Cell[BoxData[Cell[TextData[{
  Cell[BoxData[
   DynamicBox[ToBoxes[
     If[CurrentValue[
        EvaluationCell[], "CellGroupOpen"] =!= Closed, 
      Style[
       Graphics[{
         Thickness[0.18], 
         RGBColor[0.8509803921568627, 0.396078431372549, 0], 
         Line[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]}, AspectRatio -> 1, 
        PlotRange -> {{-3, 4}, {-1, 1}}, ImageSize -> 20], Magnification -> 
       0.68 Inherited], 
      Rotate[
       Style[
        Graphics[{
          Thickness[0.18], 
          RGBColor[0.8509803921568627, 0.396078431372549, 0], 
          Line[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]}, AspectRatio -> 1, 
         PlotRange -> {{-3, 4}, {-1, 1}}, ImageSize -> 20], Magnification -> 
        0.68 Inherited], Rational[1, 2] Pi, {-1.65, -1}]]],
    ImageSizeCache->{
     13.600000000000001`, {-0.1685058593749993, 13.768505859375}}]],
   ExpressionUUID->"3810e538-bf99-48f0-87c3-71a7ef98cd2c"],
  Cell[BoxData[
   TemplateBox[{1},
    "Spacer1"]],ExpressionUUID->"d6e6c460-cb2a-4d4d-975a-bd76ceeb5078"],
  "Details and Options"
 }], "NotesFrameText",ExpressionUUID->
  "ca0c77d3-9df6-4da2-b066-ca5f9b960923"]],ExpressionUUID->"7bace697-8c41-\
4eb4-8c36-1116482d313b"]], "NotesSection",
 ShowGroupOpener->"Thumbnail",
 WholeCellGroupOpener->True,
 CellGroupingRules->{"SectionGrouping", 50},
 CacheGraphics->False,
 CellID->338339025,ExpressionUUID->"1efa2449-edf0-4593-aa84-053f90e41fde"],

Cell[TextData[{
 "English runs about ",
 Cell[BoxData["0.066"], "InlineFormula",
  FontFamily->"Source Sans Pro",
  FontSize->0.9 Inherited,ExpressionUUID->
  "ca20263d-8c05-493a-92a3-31447ccda1c1"],
 "; a uniform 26-letter distribution is about ",
 Cell[BoxData["0.038"], "InlineFormula",
  FontFamily->"Source Sans Pro",
  FontSize->0.9 Inherited,ExpressionUUID->
  "9da3f433-cdf6-4833-adb2-06be33b0d32e"],
 "."
}], "Notes",ExpressionUUID->"84ddcfe5-fb5c-45ff-95f2-28c26909337d"],

Cell[TextData[{
 "The statistic separates the cipher classes: a transposition or a \
monoalphabetic substitution keeps an English-level IC, while a \
poly-alphabetic cipher (Vigenere, Quagmire) flattens it toward ",
 Cell[BoxData["0.038"], "InlineFormula",
  FontFamily->"Source Sans Pro",
  FontSize->0.9 Inherited,ExpressionUUID->
  "50208349-8b2f-4755-8013-0dca2e8c5cc8"],
 ". That difference is the entry point for ",
 Cell[BoxData[
  TemplateBox[{
    Cell[
     TextData["CipherPeriods"]], 
    "paclet:WolframInstitute/Puzzles/ref/CipherPeriods", 
    "WolframInstitute/Puzzles Package Symbol"},
   "PackageLink",
   BaseStyle->"InlineFormula"]], "InlineFormula",
  FontFamily->"Source Sans Pro",ExpressionUUID->
  "97fbfd89-da50-4e18-9f1e-ca5789eb49c6"],
 " and ",
 Cell[BoxData[
  TemplateBox[{
    Cell[
     TextData["VigenereSolve"]], 
    "paclet:WolframInstitute/Puzzles/ref/VigenereSolve", 
    "WolframInstitute/Puzzles Package Symbol"},
   "PackageLink",
   BaseStyle->"InlineFormula"]], "InlineFormula",
  FontFamily->"Source Sans Pro",ExpressionUUID->
  "ef8d2ae0-81c6-469b-b4df-7f89044c0abe"],
 "."
}], "Notes",ExpressionUUID->"d8f7df38-473c-4161-90b3-d95a6887b1a9"],

Cell[TextData[{
 "Non-letters are ignored; text with fewer than two letters gives ",
 Cell[BoxData["0"], "InlineFormula",
  FontFamily->"Source Sans Pro",
  FontSize->0.9 Inherited,ExpressionUUID->
  "1ad54776-f0b5-45f3-84b2-b6a8b612683e"],
 "."
}], "Notes",ExpressionUUID->"836fb862-61c4-4356-b97f-4c811b894d05"]
}, Closed]],

Cell["", "PageDelimiter",ExpressionUUID->"fb6ee85c-d0ad-40bc-814c-9c79c1772b20"],

Cell[CellGroupData[{

Cell[TextData[{
 Cell[BoxData[
  DynamicBox[ToBoxes[
    If[
     MatchQ[
      CurrentValue[
       EvaluationNotebook[], {
       TaggingRules, "Openers", "PrimaryExamplesSection"}, Open], 
      Alternatives[True, Open]], 
     Style[
      Graphics[{
        Thickness[0.18], 
        RGBColor[0.8509803921568627, 0.396078431372549, 0], 
        Line[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]}, AspectRatio -> 1, 
       PlotRange -> {{-3, 4}, {-1, 1}}, ImageSize -> 20], Magnification -> 
      0.68 Inherited], 
     Rotate[
      Style[
       Graphics[{
         Thickness[0.18], 
         RGBColor[0.8509803921568627, 0.396078431372549, 0], 
         Line[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]}, AspectRatio -> 1, 
        PlotRange -> {{-3, 4}, {-1, 1}}, ImageSize -> 20], Magnification -> 
       0.68 Inherited], Rational[1, 2] Pi, {-1.65, -1}]]],
   ImageSizeCache->{
    13.600000000000001`, {4.251494140625001, 9.348505859375}}]],
  ExpressionUUID->"931c09f3-108f-4ece-8d29-bfc8e94c9318"],
 Cell[BoxData[
  TemplateBox[{1},
   "Spacer1"]],ExpressionUUID->"9806dde7-b781-4ae5-8eb0-6c11ff861f70"],
 "Examples",
 "\[NonBreakingSpace]\[NonBreakingSpace]",
 Cell["(1)", "ExampleCount",ExpressionUUID->
  "7203628f-efd8-4379-89e5-78f7cbf60226"]
}], "PrimaryExamplesSection",
 WholeCellGroupOpener->True,
 CacheGraphics->False,
 CellID->2074779566,ExpressionUUID->"239bea59-015d-4efa-886e-9a7e453ca9e9"],

Cell[BoxData[
 RowBox[{"Needs", "[", "\"\<WolframInstitute`Puzzles`\>\"", "]"}]], "Input", \
"ExampleInitialization",
 CellLabel->"In[1]:=",
 CellID->1969679695,ExpressionUUID->"84a2511c-4234-4f70-91c8-6b88d31970a8"],

Cell[CellGroupData[{

Cell[TextData[{
 Cell[BoxData[
  DynamicBox[ToBoxes[
    If[CurrentValue[
       EvaluationCell[], "CellGroupOpen"] =!= Closed, 
     Style[
      Graphics[{
        Thickness[0.18], 
        RGBColor[0.8509803921568627, 0.396078431372549, 0], 
        Line[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]}, AspectRatio -> 1, 
       PlotRange -> {{-3, 4}, {-1, 1}}, ImageSize -> 20], Magnification -> 
      0.68 Inherited], 
     Rotate[
      Style[
       Graphics[{
         Thickness[0.18], 
         RGBColor[0.8509803921568627, 0.396078431372549, 0], 
         Line[{{-1.8, 0.5}, {0, 0}, {1.8, 0.5}}]}, AspectRatio -> 1, 
        PlotRange -> {{-3, 4}, {-1, 1}}, ImageSize -> 20], Magnification -> 
       0.68 Inherited], Rational[1, 2] Pi, {-1.65, -1}]]]]],ExpressionUUID->
  "2dab787d-0211-4a2f-9219-7dbc104875d2"],
 Cell[BoxData[
  TemplateBox[{1},
   "Spacer1"]],ExpressionUUID->"3fb1ee62-aab8-402c-82bf-1ef1d2554b0f"],
 "Basic Examples",
 "\[NonBreakingSpace]\[NonBreakingSpace]",
 Cell["(1)", "ExampleCount",ExpressionUUID->
  "9b4e9c03-bab1-46be-ac28-4f691eb4457c"]
}], "ExampleSection", "ExampleSection",
 WholeCellGroupOpener->True,
 CacheGraphics->False,
 CellID->2128189423,ExpressionUUID->"2a1e0075-40b0-4a21-9cc1-2ba6488ceb17"],

Cell["\<\
English plaintext (the decrypted Kryptos K1) sits near 0.066:\
\>", "ExampleText",ExpressionUUID->"6eca24a6-502b-4317-b094-cf3a9dada77d"],

Cell[CellGroupData[{

Cell[BoxData[
 RowBox[{"Round", "[", 
  RowBox[{
   RowBox[{
   "IndexOfCoincidence", 
    "[", "\"\<BETWEENSUBTLESHADINGANDTHEABSENCEOFLIGHTLIESTHENUANCEOFIQLUSION\
\>\"", "]"}], ",", " ", "0.001"}], "]"}]], "Input",
 CellProlog:>Needs["WolframInstitute`Puzzles`"],
 CellLabel->"In[1]:=",ExpressionUUID->"d0b47a19-a336-4d14-bb4e-67a553d3aa2c"],

Cell[BoxData["0.065`"], "Output",
 CellLabel->"Out[1]= ",ExpressionUUID->"15d1daa0-7b7a-431c-9241-54acb2cd3ce8"]
}, Open  ]]
}, Open  ]]
}, Open  ]],

Cell[BoxData[GridBox[{
   {
    DynamicBox[FEPrivate`ImportImage[
      FrontEnd`FileName[{"Documentation", "FooterIcons"}, 
       "RelatedFunction.png"]],
     ImageSizeCache->{50., {26.47265625, 33.52734375}}], GridBox[{
      {
       StyleBox[
        RowBox[{"See", " ", "Also"}], "SeeAlsoSection"]},
      {Cell[TextData[{
        Cell[BoxData[
         TemplateBox[{
           Cell[
            TextData["CipherPeriods"]], 
           "paclet:WolframInstitute/Puzzles/ref/CipherPeriods", 
           "WolframInstitute/Puzzles Package Symbol"},
          "PackageLink",
          BaseStyle->"InlineFormula"]], "InlineFormula",
         FontFamily->"Source Sans Pro",ExpressionUUID->
         "23152043-cc99-4cb3-b54b-99adeff8e6fa"],
        "\[NonBreakingSpace]",
        StyleBox[
        "\[MediumSpace]\[FilledVerySmallSquare]\[MediumSpace]", 
         "InlineSeparator"],
        " ",
        Cell[BoxData[
         TemplateBox[{
           Cell[
            TextData["VigenereSolve"]], 
           "paclet:WolframInstitute/Puzzles/ref/VigenereSolve", 
           "WolframInstitute/Puzzles Package Symbol"},
          "PackageLink",
          BaseStyle->"InlineFormula"]], "InlineFormula",
         FontFamily->"Source Sans Pro",ExpressionUUID->
         "b4a33ca1-75c2-48dd-b2eb-efd2936ad58b"],
        "\[NonBreakingSpace]",
        StyleBox[
        "\[MediumSpace]\[FilledVerySmallSquare]\[MediumSpace]", 
         "InlineSeparator"],
        " ",
        Cell[BoxData[
         TemplateBox[{
           Cell[
            TextData["EnglishNgramScore"]], 
           "paclet:WolframInstitute/Puzzles/ref/EnglishNgramScore", 
           "WolframInstitute/Puzzles Package Symbol"},
          "PackageLink",
          BaseStyle->"InlineFormula"]], "InlineFormula",
         FontFamily->"Source Sans Pro",ExpressionUUID->
         "6e1d3d75-5f65-41e2-81f2-ba2c1d500a94"]
       }], "SeeAlso",ExpressionUUID->"f3019e16-278a-4d02-b371-6306b31acdb5"]}
     }]}
  }]], "SeeAlsoSection",ExpressionUUID->"8a41e4fd-94f5-4824-bbdb-\
7e6bd43d5ad1"],

Cell[BoxData[GridBox[{
   {
    DynamicBox[FEPrivate`ImportImage[
      FrontEnd`FileName[{"Documentation", "FooterIcons"}, "RelatedGuide.png"]],
     ImageSizeCache->{50., {26.47265625, 33.52734375}}], GridBox[{
      {
       StyleBox[
        RowBox[{"Related", " ", "Guides"}], "MoreAboutSection"]},
      {
       RowBox[{"\[FilledVerySmallSquare]", Cell[BoxData[
         TemplateBox[{
           Cell[
            TextData["Search"]], 
           "paclet:WolframInstitute/Puzzles/guide/Search"},
          "RefLinkPlain",
          BaseStyle->{"MoreAbout"}]], "MoreAbout",ExpressionUUID->
         "e8043d22-4725-43f0-8d72-ca4767ccfffd"]}]}
     }]}
  }]], "MoreAboutSection",ExpressionUUID->"13c861e8-71e7-4fe5-97b6-\
835bbc92245a"],

Cell[" ", "FooterCell",ExpressionUUID->"7c1e5607-331a-45df-bcce-124cf47534bb"]
},
Saveable->False,
ScreenStyleEnvironment->"Working",
WindowSize->{900, 830},
WindowMargins->{{0, Automatic}, {Automatic, 0}},
WindowTitle->"IndexOfCoincidence",
TaggingRules->{
 "ModificationHighlight" -> False, "ColorType" -> "", "LinkTrails" -> "", 
  "ExampleCounter" -> 1, 
  "Openers" -> {
   "PrimaryExamplesSection" -> Open, "ExampleSection" -> {"0" -> Open}, 
    "AllOptsTable" -> Closed}, "NewStyles" -> True, 
  "CitationPopupData" -> $Failed, "ShowCitation" -> False, "HasOptions" -> 
  True, "RootCaptions" -> "", "HeaderCoreAreaLink" -> {}, 
  "Metadata" -> {
   "built" -> "{2026, 8, 27, 0, 11, 52.991814}", 
    "history" -> {"XX", "", "", ""}, "context" -> "WolframInstitute`Puzzles`",
     "keywords" -> {}, "specialkeywords" -> {}, 
    "tutorialcollectionlinks" -> {}, "index" -> True, "label" -> 
    "Wolfram Institute/ Puzzles Symbol", "language" -> "en", "paclet" -> 
    "WolframInstitute/Puzzles", "status" -> "None", "summary" -> 
    "PackageLink[IndexOfCoincidence, paclet : \
WolframInstitute/Puzzles/ref/IndexOfCoincidence, WolframInstitute/Puzzles \
Package Symbol][text] gives the index of coincidence of the letters in text: \
the probability that two letters drawn from it without replacement are \
equal.", "synonyms" -> {}, "tabletags" -> {}, "title" -> "IndexOfCoincidence",
     "titlemodifier" -> "", "metadescription" -> "", "windowtitle" -> 
    "IndexOfCoincidence", "type" -> "Symbol", "uri" -> 
    "WolframInstitute/Puzzles/ref/IndexOfCoincidence", "WorkflowDockedCell" -> 
    ""}, "SearchTextTranslated" -> ""},
CellContext->CellGroup,
FrontEndVersion->"15.0 for Mac OS X ARM (64-bit) (May 19, 2026)",
StyleDefinitions->FrontEnd`FileName[{"Wolfram"}, "Reference.nb"],
ExpressionUUID->"fdaa7b64-fd90-40c9-9b71-4f1afc440ccf"
]
(* End of Notebook Content *)

(* Internal cache information *)
(*CellTagsOutline
CellTagsIndex->{}
*)
(*CellTagsIndex
CellTagsIndex->{}
*)
(*NotebookFileOutline
Notebook[{
Cell[586, 21, 5436, 135, 70, "AnchorBarGrid",ExpressionUUID->"8edc7082-4deb-4f5e-92c5-252dbcd0dc9c",
 CellID->1],
Cell[6025, 158, 107, 0, 70, "ContextNameCell",ExpressionUUID->"258627a4-a553-4ac3-a8c0-7d7922e7eaa9"],
Cell[CellGroupData[{
Cell[6157, 162, 561, 14, 70, "ObjectNameGrid",ExpressionUUID->"34078166-6906-49dd-9b1e-5d4106b8d7ab"],
Cell[6721, 178, 836, 19, 70, "Usage",ExpressionUUID->"918c3f12-e51b-4c73-8c4e-f1073da95ccc"]
}, Open  ]],
Cell[CellGroupData[{
Cell[7594, 202, 1443, 34, 70, "NotesSection",ExpressionUUID->"1efa2449-edf0-4593-aa84-053f90e41fde",
 CellGroupingRules->{"SectionGrouping", 50},
 CellID->338339025],
Cell[9040, 238, 481, 12, 70, "Notes",ExpressionUUID->"84ddcfe5-fb5c-45ff-95f2-28c26909337d"],
Cell[9524, 252, 1186, 31, 70, "Notes",ExpressionUUID->"d8f7df38-473c-4161-90b3-d95a6887b1a9"],
Cell[10713, 285, 313, 7, 70, "Notes",ExpressionUUID->"836fb862-61c4-4356-b97f-4c811b894d05"]
}, Closed]],
Cell[11041, 295, 80, 0, 70, "PageDelimiter",ExpressionUUID->"fb6ee85c-d0ad-40bc-814c-9c79c1772b20"],
Cell[CellGroupData[{
Cell[11146, 299, 1401, 37, 70, "PrimaryExamplesSection",ExpressionUUID->"239bea59-015d-4efa-886e-9a7e453ca9e9",
 CellID->2074779566],
Cell[12550, 338, 216, 4, 70, "Input",ExpressionUUID->"84a2511c-4234-4f70-91c8-6b88d31970a8",
 CellID->1969679695],
Cell[CellGroupData[{
Cell[12791, 346, 1236, 31, 70, "ExampleSection",ExpressionUUID->"2a1e0075-40b0-4a21-9cc1-2ba6488ceb17",
 CellID->2128189423],
Cell[14030, 379, 147, 2, 70, "ExampleText",ExpressionUUID->"6eca24a6-502b-4317-b094-cf3a9dada77d"],
Cell[CellGroupData[{
Cell[14202, 385, 344, 8, 70, "Input",ExpressionUUID->"d0b47a19-a336-4d14-bb4e-67a553d3aa2c"],
Cell[14549, 395, 112, 1, 70, "Output",ExpressionUUID->"15d1daa0-7b7a-431c-9241-54acb2cd3ce8"]
}, Open  ]]
}, Open  ]]
}, Open  ]],
Cell[14700, 401, 2050, 53, 70, "SeeAlsoSection",ExpressionUUID->"8a41e4fd-94f5-4824-bbdb-7e6bd43d5ad1"],
Cell[16753, 456, 740, 19, 70, "MoreAboutSection",ExpressionUUID->"13c861e8-71e7-4fe5-97b6-835bbc92245a"],
Cell[17496, 477, 78, 0, 70, "FooterCell",ExpressionUUID->"7c1e5607-331a-45df-bcce-124cf47534bb"]
}
]
*)

(* End of internal cache information *)

