For the purposes of this Part—
"tenant" means a person to whom—
a domestic PR property is let on a tenancy which falls within section 42(1)(a) of the Act, or
a non-domestic PR property is let,
"landlord" means a person who lets, or proposes to let—
a domestic PR property on a tenancy which falls within section 42(1)(a) of the Act, or
a non-domestic PR property.