anchor.diff:  let seekReadTypeDefRowUncached ctxtH idx =
       let ctxt = getHole ctxtH
       count ctxt.countTypeDef;
  -    let addr = ctxt.rowAddr TableNames.TypeDef idx
  -    seek ctxt.is addr;
  -    let flags = readInt32 ctxt.is
  -    let nameIdx = readStringIdx ctxt
  -    let namespaceIdx = readStringIdx ctxt
  -    let extendsIdx = readTypeDefOrRefOrSpecIdx ctxt
  -    let fieldsIdx = readUntaggedIdx TableNames.Field ctxt
  -    let methodsIdx = readUntaggedIdx TableNames.Method ctxt
  +    let mutable addr = ctxt.rowAddr TableNames.TypeDef idx
  +    let flags = seekReadInt32Adv ctxt &addr
  +    let nameIdx = seekReadStringIdx ctxt &addr
  +    let namespaceIdx = seekReadStringIdx ctxt &addr
  +    let extendsIdx = seekReadTypeDefOrRefOrSpecIdx ctxt &addr
  +    let fieldsIdx = seekReadUntaggedIdx TableNames.Field ctxt &addr
  +    let methodsIdx = seekReadUntaggedIdx TableNames.Method ctxt &addr
       (flags, nameIdx, namespaceIdx, extendsIdx, fieldsIdx, methodsIdx) 
   
   /// Read Table Field 
   let seekReadFieldRow ctxt idx =
       count ctxt.countField;
  -    let addr = ctxt.rowAddr TableNames.Field idx
  -    seek ctxt.is addr;
  -    let flags = readUInt16AsInt32 ctxt.is
  -    let nameIdx = readStringIdx ctxt
  -    let typeIdx = readBlobIdx ctxt
  +    let mutable addr = ctxt.rowAddr TableNames.Field idx
  +    let flags = seekReadUInt16AsInt32Adv ctxt &addr
  +    let nameIdx = seekReadStringIdx ctxt &addr
  +    let typeIdx = seekReadBlobIdx ctxt &addr
       (flags,nameIdx,typeIdx)  
   
   /// Read Table Method 
   let seekReadMethodRow ctxt idx =
       count ctxt.countMethod;
  -    let addr = ctxt.rowAddr TableNames.Method idx
  -    seek ctxt.is addr;
  -    let codeRVA = readInt32 ctxt.is
  -    let implflags = readUInt16AsInt32 ctxt.is
  -    let flags = readUInt16AsInt32 ctxt.is
  -    let nameIdx = readStringIdx ctxt
  -    let typeIdx = readBlobIdx ctxt
  -    let paramIdx = readUntaggedIdx TableNames.Param ctxt
  +    let mutable addr = ctxt.rowAddr TableNames.Method idx
  +    let codeRVA = seekReadInt32Adv ctxt &addr
  +    let implflags = seekReadUInt16AsInt32Adv ctxt &addr
  +    let flags = seekReadUInt16AsInt32Adv ctxt &addr
  +    let nameIdx = seekReadStringIdx ctxt &addr
  +    let typeIdx = seekReadBlobIdx ctxt &addr
  +    let paramIdx = seekReadUntaggedIdx TableNames.Param ctxt &addr
       (codeRVA, implflags, flags, nameIdx, typeIdx, paramIdx) 
   
   /// Read Table Param 
   let seekReadParamRow ctxt idx =
       count ctxt.countParam;
  -    let addr = ctxt.rowAddr TableNames.Param idx
  -    seek ctxt.is addr;
  -    let flags = readUInt16AsInt32 ctxt.is
  -    let seq =  (readUInt16AsInt32 ctxt.is)
  -    let nameIdx = readStringIdx ctxt
  +    let mutable addr = ctxt.rowAddr TableNames.Param idx
  +    let flags = seekReadUInt16AsInt32Adv ctxt &addr
  +    let seq =  seekReadUInt16AsInt32Adv ctxt &addr
  +    let nameIdx = seekReadStringIdx ctxt &addr
       (flags,seq,nameIdx) 
   
   /// Read Table InterfaceImpl 
  
positive.code: let seekReadInterfaceImplRowUncached ctxtH idx =
      let ctxt = getHole ctxtH
      count ctxt.countInterfaceImpl;
      let addr = ctxt.rowAddr TableNames.InterfaceImpl idx
      seek ctxt.is addr;
      let tidx = readUntaggedIdx TableNames.TypeDef ctxt
      let intfIdx = readTypeDefOrRefOrSpecIdx ctxt
      (tidx,intfIdx)
  
  /// Read Table MemberRef 
  let seekReadMemberRefRow ctxt idx =
      count ctxt.countMemberRef;
      let addr = ctxt.rowAddr TableNames.MemberRef idx
      seek ctxt.is addr;
      let mrpIdx = readMemberRefParentIdx ctxt
      let nameIdx = readStringIdx ctxt
      let typeIdx = readBlobIdx ctxt
      (mrpIdx,nameIdx,typeIdx) 
  
  /// Read Table Constant 
  
negative.code: 
  let OpenILModuleReaderFromBytes fileNameForDebugOutput bytes opts = 
          assert opts.pdbPath.IsNone
          let mc = ByteFile.OpenBytes bytes
          let modul,ilAssemblyRefs,pdb = genOpenBinaryReader fileNameForDebugOutput mc opts
          let ilModuleReader = 
              { modul = modul; 
                ilAssemblyRefs = ilAssemblyRefs
  