A tuple is a fixed fixed-length list containing elements that need not have the same type. It can be, and often is, used as a key-value pair. A row (sometimes called a record) is the set of fields within a table that are relevant to a specific entity.
The stem wall on a concrete foundation is essentially the supporting wall that joins the foundation of a building to the vertical walls of the structure that is constructed atop the foundation.
R403.1.3.1 Foundations with stemwalls. Foundationswith stem walls shall have installed a minimum of oneNo.4barwithin12inches(305mm)ofthetopofthewalland one No. 4 bar located 3 inches (76 mm) to 4 inches(102 mm) from the bottom of the footing.