My view is that vij = 7. The j signifies it is the last i in a roman numeral. So we have vij = vii, ie 7.
From Wiki for 'J' - The letter 'J' originated as a swash letter I, used for the letter 'I' at the end of Roman numerals when following another 'I', as in 'XXIIJ' instead of 'XXIII' for the Roman numeral representing 23.
Ken