sample refSampleArray[ X - xD, y ] and the sample refSampleArray[ x, y y y ] are marked as "available for Intra_Base prediction", the following ordered steps are specified: a. A variable cornerSampleAvailableFlag is derived as follows: If the sample refSampleArray[ x - xD, y - yD ] is marked as "available for ntra_Base prediction", the variable cornerSampleAvailableFlag is set equal to 1. Otherwise (the sample refSampleArray[x- xD, y - yD ] is marked as "not available for Intra Base prediction"), the variable cornerSampleAvailable is set equal to 0. The diagonal construction process for not available sample values as specified in clause G.8.6.2.2.2.1 is invoked with refArrayW refArrayH, refSampleArray, the sample location difference (xD, yD ), the sample location x, y ), and the variable cornerSampleAvailableFlag as the inputs and the output is the sample array refSampleArray with a modified sample value at sample location (x,y). Otherwise (the sample refSampleArray[ - xD, y ] or the sample refSampleArray[x,y- yD ] is marked as "not available for Intra_Base prediction"), the following applies: If the sample refSampleArray[ x - xD, - y ] is marked as "available for Intra Base prediction", the sample value refSampleArray[ x, y ] is set equal to refSampleArray[ X - xD, y ]. Otherwise, if the sample refSampleArray[ x, y y y D ] - is marked as "available for Intra Base prediction", the sample value refSampleArray[ X, y ] is set equal to refSampleArray[ X, yD ]. Otherwise, if the sample refSampleArray[ X - xD, y-yD] is marked as "available for Intra Base prediction", the sample value refSampleArray[ X, ] is set equal to refSampleArray[ X - xD, y yD ]. Otherwise (the samples refSampleArray[ X - xD, ] y ], refSampleArray[ x, y y y D , refSampleArray[ - are marked as "not available for Intra_Base prediction"), the sample value refSampleArray| x, y ] is not modified. All samples refSampleArray[ X, y ] with x=0..(refArrayW - 1) and y=0. (refArrayH - 1) are marked as "available for Intra_Base prediction". G.8.6.2.2.2.1 Diago