tract of real property
For purposes of this section, the term “tract of real property” means a single piece of real property, except that 2 or more pieces of real property shall be considered a tract if at any time they were contiguous in the hands of the taxpayer or if they would be contiguous except for the interposition of a road, street, railroad, stream, or similar property. If, following the sale or exchange of any lot or parcel from a tract of real property, no further sales or exchanges of any other lots or parcels from the remainder of such tract are made for a period of 5 years, such remainder shall be deemed a tract.