Erect means build or upright. If you erect a house, you build it. If you stand erect, you hold your body as tall as possible.
A mathematical model is a description of a system using mathematical concepts and language.The process of building a mathematical model is termed mathematical modeling.Mathematical models are used in the natural sciences (such as physics, biology, earth science, meteorology) and engineering disciplines (e.g. computer science, artificial intelligence). mathematical model is a description of a system using mathematical concepts and language.
branch of mathematicsmathematics, deductive study of numbers, geometry, and various abstract constructs, or structures; the latter often abstract the features common to several models derived from the empirical, or applied, sciences, although many emerge from purely mathematical or logical. ..... Click the link for more information.