The effect of these deeming provisions is that it is the beneficiary rather than the trustee who is treated as the buyer (or as holding, or disposing of, an interest in a dwelling).
Effaith y darpariaethau tybio hyn yw mai'r buddiolwr yn hytrach na'r ymddiriedolwr sy'n cael ei drin fel y prynwr (neu'r sawl sy'n dal neu'n gwaredu buddiant mewn annedd).