Types and uses of mathematical expressions

The article describes the role of mathematics in the world, its history and development. There is also talk of mathematical expressions, of several types. And in general, they enriched the science of mathematics with new creative discoveries. But math there are such misconceptions in the history of Central Asia in the IX-XV centuries has no math news. The definition of this value depends on the semantics assigned to the expression symbols. These semantic rules may declare that some expressions do not define any value (for example, when they include division by 0).