The language of mathematics is the system used by mathematicians to communicate mathematical ideas among themselves. This language consists of a substrate of some natural language (for example English) using technical terms and grammatical conventions that are peculiar to mathematical discourse (see Mathematical jargon), supplemented by a highly specialized symbolic notation for mathematical formulas.
Like natural languages in general, discourse using the language of mathematics can employ a scala of registers. Research articles in academic journals are sources for detailed theoretical discussions about ideas concerning mathematics and its implications for society.
Here are some definitions of language:
These definitions describe language in terms of the following components:
Each of these components is also found in the language of mathematics.
Mathematical notation is central to the power of modern mathematics. Though the algebra of Al-Khwārizmī did not use such symbols, it solved equations using many more rules than are used today with symbolic notation, and had great difficulty working with multiple variables (which using symbolic notation can simply be called , etc.). Sometimes formulas cannot be understood without a written or spoken explanation, but often they are sufficient by themselves, and sometimes they are difficult to read aloud or information is lost in the translation to words, as when several parenthetical factors are involved or when a complex structure like a matrix is manipulated.
Like any other profession, mathematics also has its own brand of technical terminology. In some cases, a word in general usage has a different and specific meaning within mathematics—examples are group, ring, field, category, term, and factor. For more examples, see Category:Mathematical terminology.
In other cases, specialist terms have been created which do not exist outside of mathematics—examples are tensor, fractal, functor. Mathematical statements have their own moderately complex taxonomy, being divided into axioms, conjectures, theorems, lemmas and corollaries. And there are stock phrases in mathematics, used with specific meanings, such as "if and only if", "necessary and sufficient" and "without loss of generality". Such phrases are known as mathematical jargon.
The vocabulary of mathematics also has visual elements. Diagrams are used informally on blackboards, as well as more formally in published work. When used appropriately, diagrams display schematic information more easily. Diagrams also help visually and aid intuitive calculations. Sometimes, as in a visual proof, a diagram even serves as complete justification for a proposition. A system of diagram conventions may evolve into a mathematical notation – for example, the Penrose graphical notation for tensor products.
The mathematical notation used for formulas has its own grammar, not dependent on a specific natural language, but shared internationally by mathematicians regardless of their mother tongues. This includes the conventions that the formulas are written predominantly left to right, even when the writing system of the substrate language is right-to-left, and that the Latin alphabet is commonly used for simple variables and parameters. A formula such as
is understood by Chinese and Syrian mathematicians alike.
Such mathematical formulas can be a part of speech in a natural-language phrase, or even assume the role of a full-fledged sentence. For example, the formula above, an inequation, can be considered a sentence or an independent clause in which the greater than or equal to symbol has the role of a symbolic verb. In careful speech, this can be made clear by pronouncing "≥" as "is greater than or equal to", but in an informal context mathematicians may shorten this to "greater or equal" and yet handle this grammatically like a verb. A good example is the book title Why does E = mc2?; here, the equals sign has the role of an infinitive.
Mathematical formulas can be vocalized (spoken aloud). The vocalization system for formulas has to be learned, and is dependent on the underlying natural language. For example, when using English, the expression "ƒ(x)" is conventionally pronounced "eff of eks", where the insertion of the preposition "of" is not suggested by the notation per se. The expression "", on the other hand, is commonly vocalized like "dee-why-dee-eks", with complete omission of the fraction bar, in other contexts often pronounced "over". The book title Why does E = mc2? is said aloud as Why does ee equal em see-squared?.
As is the case for spoken mathematical language, in written or printed mathematical discourse, mathematical expressions containing a symbolic verb, like , are generally treated as clauses (dependent or independent) in sentences or as complete sentences and are punctuated as such by mathematicians and theoretical physicists. In particular, this is true for both inline and displayed expressions. In contrast, writers in other natural sciences disciplines may try to avoid using equations within sentences and may treat displayed expressions in the same way as figures or schemes.
As an example, a mathematician might write:
In this statement, "" (in which is read as "ay en" or perhaps, more formally, as "the sequence ay en") and "" are treated as nouns, while "" (read: the limit of as n tends to infinity equals 'big A'), "", and "" are read as independent clauses, and "" is read as "the equation equals plus ". Moreover, the sentence ends after the displayed equation, as indicated by the period after "". In terms of typesetting conventions, broadly speaking, standard mathematical functions such as sin and operations such as + as well as punctuation symbols including the various brackets are set in roman type while Latin alphabet variables are set in italics. Matrices, vectors, and other objects made up of components are set in bold roman. (There is some disagreement as to whether the standard constants (e.g., e, π, i = (–1)1/2) or the "d" in dy/dx should be italicized. Greek letters are also usually set upright instead of slanted.) There are also a number of conventions for the part of the alphabet from which variable names are chosen. For example, i, j, k, l, m, n are usually reserved for integers, w and z are often used for complex numbers, while a, b, c, α, β, γ are used for real numbers. The letters x, y, z are frequently used for unknowns to be found or as arguments of a function, while a, b, c are used for coefficients and f, g, h are used as names of functions. These conventions are not hard rules.
Definitions are signaled by words like "we call", "we say", or "we mean" or by statements like "An [object] is [word to be defined] if [condition]" (for example, "A set is closed if it contains all of its limit points."). As a special convention, the word "if" in such a definition should be interpreted as "if and only if".
Theorems have generally a title or label in bold type, and possibly identify the originator (for example, "Theorem 1.4 (Weyl)."). This is immediately followed by the statement of the theorem, usually set in italics. The proof of a theorem is usually clearly delimited, starting with the word Proof while the end of the proof is indicated by a halmos or another symbol, or by the letters Q.E.D..
Mathematics is used by mathematicians, who form a global community composed of speakers of many languages. It is also used by students of mathematics. As mathematics is a part of primary education in almost all countries, almost all educated people have some exposure to pure mathematics. There are very few cultural dependencies or barriers in modern mathematics. There are international mathematics competitions, such as the International Mathematical Olympiad, and international co-operation between professional mathematicians is commonplace.
Mathematics is used to communicate information about a wide range of different subjects. Here are three broad categories:
Some definitions of language, such as early versions of Charles Hockett's "design features" definition, emphasize the spoken nature of language. Mathematics would not qualify as a language under these definitions, as it is primarily a written form of communication (to see why, try reading Maxwell's equations out loud). However, these definitions would also disqualify sign languages, which are now recognized as languages in their own right, independent of spoken language.
Other linguists believe no valid comparison can be made between mathematics and language, because they are simply too different: