diff --git a/playground.fsx b/playground.fsx
index 1a1fea6d..cc931a9f 100644
--- a/playground.fsx
+++ b/playground.fsx
@@ -1,27 +1,161 @@
-#load "src/FsSpreadsheet/FsAddress.fs"
-#load "src/FsSpreadsheet/Cells/FsCell.fs"
-#load "src/FsSpreadsheet/Cells/FsCellsCollection.fs"
-#load "src/FsSpreadsheet/Ranges/FsRangeAddress.fs"
-#load "src/FsSpreadsheet/Ranges/FsRangeBase.fs"
-#load "src/FsSpreadsheet/Ranges/FsRangeRow.fs"
-#load "src/FsSpreadsheet/Ranges/FsRangeColumn.fs"
-#load "src/FsSpreadsheet/Ranges/FsRange.fs"
-#load "src/FsSpreadsheet/Tables/FsTableField.fs"
-#load "src/FsSpreadsheet/Tables/FsTableRow.fs"
-#load "src/FsSpreadsheet/Tables/FsTable.fs"
-#load "src/FsSpreadsheet/FsRow.fs"
-#load "src/FsSpreadsheet/FsWorksheet.fs"
-#load "src/FsSpreadsheet/FsWorkbook.fs"
 #r "nuget: DocumentFormat.OpenXml"
-#load "src/FsSpreadsheet.ExcelIO/SharedStringTable.fs"
-#load "src/FsSpreadsheet.ExcelIO/Cell.fs"
-#load "src/FsSpreadsheet.ExcelIO/CellData.fs"
-#load "src/FsSpreadsheet.ExcelIO/Row.fs"
-#load "src/FsSpreadsheet.ExcelIO/SheetData.fs"
-#load "src/FsSpreadsheet.ExcelIO/Sheet.fs"
-#load "src/FsSpreadsheet.ExcelIO/Table.fs"
-#load "src/FsSpreadsheet.ExcelIO/WorkSheet.fs"
-#load "src/FsSpreadsheet.ExcelIO/Workbook.fs"
-#load "src/FsSpreadsheet.ExcelIO/Spreadsheet.fs"
-#load "src/FsSpreadsheet.ExcelIO/FsExtensions.fs"
+//#load "src/FsSpreadsheet/FsAddress.fs"
+//#load "src/FsSpreadsheet/Cells/FsCell.fs"
+//#load "src/FsSpreadsheet/Cells/FsCellsCollection.fs"
+//#load "src/FsSpreadsheet/Ranges/FsRangeAddress.fs"
+//#load "src/FsSpreadsheet/Ranges/FsRangeBase.fs"
+//#load "src/FsSpreadsheet/Ranges/FsRangeRow.fs"
+//#load "src/FsSpreadsheet/Ranges/FsRangeColumn.fs"
+//#load "src/FsSpreadsheet/Ranges/FsRange.fs"
+//#load "src/FsSpreadsheet/Tables/FsTableField.fs"
+//#load "src/FsSpreadsheet/Tables/FsTableRow.fs"
+//#load "src/FsSpreadsheet/Tables/FsTable.fs"
+//#load "src/FsSpreadsheet/FsRow.fs"
+//#load "src/FsSpreadsheet/FsWorksheet.fs"
+//#load "src/FsSpreadsheet/FsWorkbook.fs"
+//#load "src/FsSpreadsheet/DSL/Expression.fs"
+//#load "src/FsSpreadsheet/DSL/Types.fs"
+//#load "src/FsSpreadsheet/DSL/CellBuilder.fs"
+//#load "src/FsSpreadsheet/DSL/RowBuilder.fs"
+//#load "src/FsSpreadsheet/DSL/ColumnBuilder.fs"
+//#load "src/FsSpreadsheet/DSL/TableBuilder.fs"
+//#load "src/FsSpreadsheet/DSL/SheetBuilder.fs"
+//#load "src/FsSpreadsheet/DSL/WorkbookBuilder.fs"
+//#load "src/FsSpreadsheet/DSL/DSL.fs"
+//#load "src/FsSpreadsheet/DSL/Operators.fs"
+//#load "src/FsSpreadsheet/DSL/Transform.fs"
+//#load "src/FsSpreadsheet.CsvIO/FsExtension.fs"
+//#load "src/FsSpreadsheet.ExcelIO/SharedStringTable.fs"
+//#load "src/FsSpreadsheet.ExcelIO/Cell.fs"
+//#load "src/FsSpreadsheet.ExcelIO/CellData.fs"
+//#load "src/FsSpreadsheet.ExcelIO/Row.fs"
+//#load "src/FsSpreadsheet.ExcelIO/SheetData.fs"
+//#load "src/FsSpreadsheet.ExcelIO/Sheet.fs"
+//#load "src/FsSpreadsheet.ExcelIO/Table.fs"
+//#load "src/FsSpreadsheet.ExcelIO/WorkSheet.fs"
+//#load "src/FsSpreadsheet.ExcelIO/Workbook.fs"
+//#load "src/FsSpreadsheet.ExcelIO/Spreadsheet.fs"
+//#load "src/FsSpreadsheet.ExcelIO/FsExtensions.fs"
+#r "src/FsSpreadsheet/bin/Debug/netstandard2.0/FsSpreadsheet.dll"
+#r "src/FsSpreadsheet.CsvIO/bin/Debug/netstandard2.0/FsSpreadsheet.CsvIO.dll"
+#r "src/FsSpreadsheet.ExcelIO/bin/Debug/netstandard2.0/FsSpreadsheet.ExcelIO.dll"
 
+
+open FsSpreadsheet
+open FsSpreadsheet.ExcelIO
+open FsSpreadsheet.DSL
+open DocumentFormat.OpenXml
+
+
+// ----------------------------------------------
+
+let excelFilePath = @"C:\Users\olive\OneDrive\CSB-Stuff\testFiles\testExcel5.xlsx"
+
+let dslTree = 
+    workbook {
+        sheet "MySheet" {
+            row {
+                cell {1}
+                cell {2}
+                cell {3}
+            }
+            row {
+                4
+                5
+                6
+            }
+        }
+    }
+
+let fsWorkbook = dslTree.Value.Parse()
+fsWorkbook.ToFile(excelFilePath)
+
+let doc = Spreadsheet.fromFile excelFilePath false
+let sst = Spreadsheet.tryGetSharedStringTable doc
+let wbp = Spreadsheet.getWorkbookPart doc
+let wb = Workbook.get wbp
+let shts = Sheet.Sheets.get wb
+let shtsN = Sheet.Sheets.getSheets shts |> Array.ofSeq
+shtsN.Length
+shtsN[0].Id.Value
+let wspN =
+    shtsN
+    |> Array.map (
+        fun s -> Worksheet.WorksheetPart.getByID s.Id.Value wbp
+    )
+let tblNM = wspN |> Array.map (Worksheet.WorksheetPart.getTables >> Array.ofSeq)
+let wsN = wspN |> Array.map Worksheet.get
+let sdN = wsN |> Array.map Worksheet.getSheetData
+let rNM = sdN |> Array.map (SheetData.getRows >> Array.ofSeq)
+let cNMO =
+    rNM                                             // Level 1: Worksheets (N)
+    |> Array.map (                                  // Level 2: Rows (M)
+        Array.map (Row.toCellSeq >> Array.ofSeq)    // Level 3: Cells (O)
+    )
+let testCell = cNMO[0].[0].[0]
+let cv = Cell.getValue sst testCell
+let dt = Cell.getType testCell |> Cell.cellValuesToDataType
+let cr = Cell.getReference testCell
+let fa = FsAddress cr
+FsCell(cv, dt, fa)
+let fswb = new FsWorkbook()
+shtsN[0]
+let name = Sheet.getName shtsN[0]
+let tblN = tblNM[0]
+let fsTblN = tblN |> Array.map FsTable.fromXlsxTable
+let fsCcN = FsCellsCollection()
+fsCcN.Add
+let fswsN = 
+    shtsN
+    |> Array.mapi (
+        fun i sht -> 
+            let name = Sheet.getName sht
+            let tblN = tblNM[i]
+            let fsTblN = tblN |> Array.map FsTable.fromXlsxTable
+            let fsCcN
+            FsWorksheet(name, fsRs = , )
+    )
+
+let xlsxWorksheet = 0
+
+let toFsWorkbook spreadsheetDoc =
+    let sst = Spreadsheet.tryGetSharedStringTable spreadsheetDoc
+    let wbp = Spreadsheet.getWorkbookPart spreadsheetDoc
+    let wb = Workbook.get wbp
+    let shts = Sheet.Sheets.get wb
+    let shtsN = Sheet.Sheets.getSheets shts |> Array.ofSeq      // N, M, O = multiples of the elements, e.g. here: multiple Sheet elements
+    let wspN =
+        shtsN
+        |> Array.map (
+            fun s -> Worksheet.WorksheetPart.getByID s.Id.Value wbp
+        )
+    let tblNM = wspN |> Array.map (Worksheet.WorksheetPart.getTables >> Array.ofSeq)
+    let wsN = wspN |> Array.map Worksheet.get
+    let sdN = wsN |> Array.map Worksheet.getSheetData
+    let rNM = sdN |> Array.map (SheetData.getRows >> Array.ofSeq)
+    let cNMO =
+        rNM                                             // Level 1: Worksheets (N)
+        |> Array.map (                                  // Level 2: Rows (M)
+            Array.map (Row.toCellSeq >> Array.ofSeq)    // Level 3: Cells (O)
+        )
+    let fswb = new FsWorkbook()
+    let fswsN = 
+        shtsN
+        |> Array.mapi (
+            fun i sht -> 
+                let name = Sheet.getName sht
+                let tblN = tblNM[i]
+                let fsTblN = tblN |> Array.map FsTable.fromXlsxTable
+                let fsCcN
+                FsWorksheet(name, fsRs = , )
+        )
+    0
+
+
+let fromXlsxWorksheet xlsxWorksheet =
+    let sd = Worksheet.getSheetData xlsxWorksheet
+    xlsxWorksheet.SheetProperties.LocalName
+    FsWorksheet()
+    0
+
+doc.Close()
\ No newline at end of file