A use clause of a supermarket lease for Carr (D) provided that D would use the premises 'for the principal purpose of conducting thereon a general food supermarket.' It permitted the sale of items sold 'in other general food supermarkets.' Another clause of the supermarket lease prohibited the tenant from subleasing the premises without landlord consent. After a liquor store lease expired, D moved the liquor store in the Wasilla Shopping Center into part of the premises previously occupied by the supermarket. D did not seek or obtain from P, but P was aware of the relocation and made no objection that the relocation would violate either the use clause or the sublease clause. The complaint alleged that 'several years ago' the liquor store had been relocated to a partitioned area of the supermarket without consent and that this violated the lease's use and sublease clauses. P sought declaratory relief and a permanent injunction preventing D from operating an Oaken Keg liquor store on the supermarket premises. The court granted P's motion for summary judgment concerning the sublease clause, holding that D 'breached its duty to seek permission before sub-leasing a portion of the leased premises.' The court then ordered a trial in two phases. The first phase would be tried to the court and would concern issues relating to the use clause. The second phase would be a jury trial and would involve all other issues. The court concluded that the use clause did not permit the sale of liquor from the supermarket premises. The jury returned a special verdict finding that P suffered past damages as a result of the breach of the sublease clause of $172,490 and past damages for breach of the use clause of $50,028.78. The jury also found that CG Properties would suffer future damages flowing from the breach of the use clause of $47,847. But the jury also found that CG Properties was estopped from enforcing the use clause. The trial court rejected the jury's finding regarding estoppel. This appeal resulted. D argues the doctrines of waiver and estoppel.