Landlord and tenant – Variation of lease – Personal bar – Rei interventus – Waiver. Court of Session: In an action in which the owner of a shopping centre sought declarator that the tenant of subjects within the centre was personally barred from taking any action to prevent it from constructing a building abutting the existing centre and leasing it to another retailer, the court held that the pursuer was not entitled to declarator, not having established on grounds of the operation of statutory personal bar, or common law rei interventus, or by waiver of its right under the lease that the defender was barred from any action that would prevent the pursuer from constructing and leasing the building.