the chargeable interest has not subsequently been acquired at market value by means of a chargeable transaction where group relief was available but was not claimed.
nid yw’r buddiant trethadwy wedi’i gaffael wedi hynny am ei werth ar y farchnad drwy drafodiad trethadwy yr oedd rhyddhad grŵp ar gael mewn perthynas ag ef, ond nas hawliwyd