one sig Board {
        cols : seq Columns
} {
        #cols = 9
        not hasDups[cols]
}

sig Columns {
        cells : seq Values
} {
        #cells = 9
        elems[cells] = Values
}

abstract sig Values {}
one sig V1, V2, V3, V4, V5, V6, V7, V8, V9 extends Values {}

fun row [ i :  Int ] : Values {
	{ elems[Board.cols].cells[i] }
}

fun subsquare [ startRow : Int, startCol : Int ] : Values {
	{
		Board.cols[startCol].cells[startRow] +
	   	Board.cols[startCol].cells[startRow + 1] +
	   	Board.cols[startCol].cells[startRow + 2] +
	   	Board.cols[startCol + 1].cells[startRow] +
		Board.cols[startCol + 1].cells[startRow + 1] +
		Board.cols[startCol + 1].cells[startRow + 2] +
		Board.cols[startCol + 2].cells[startRow] +
		Board.cols[startCol + 2].cells[startRow + 1] +
		Board.cols[startCol + 2].cells[startRow + 2]
	}
}

fact EveryRowHasEveryNumber {
	all v : Values | v in row[0]
	all v : Values | v in row[1]
	all v : Values | v in row[2]
	all v : Values | v in row[3]
	all v : Values | v in row[4]
	all v : Values | v in row[5]
	all v : Values | v in row[6]
	all v : Values | v in row[7]
	all v : Values | v in row[8]
}

fact EveryColumnHasEveryNumber {
	all c : elems[Board.cols] | !c.cells.hasDups
}

fact EverySubsquareHasEveryNumber {
	all v : Values | v in subsquare[0,0]
	all v : Values | v in subsquare[0,3]
	all v : Values | v in subsquare[0,6]
	all v : Values | v in subsquare[3,0]
	all v : Values | v in subsquare[3,3]
	all v : Values | v in subsquare[3,6]
	all v : Values | v in subsquare[6,0]
	all v : Values | v in subsquare[6,3]
	all v : Values | v in subsquare[6,6]
}

pred Show[i : Int] {
        //seq[i][j] = Int[7]
        i in inds[Board.cols]
        row[i] = Values
}

run Show for 5 int, 9 seq, 9 Columns