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3.2.1 Naming Conventions
Mathematical functions in Mathematica are given names according to definite rules. As with most Mathematica functions, the names are usually complete English words, fully spelled out. For a few very common functions, Mathematica uses the traditional abbreviations. Thus the modulo function, for example, is Mod, not Modulo.
Mathematical functions that are usually referred to by a person's name have names in Mathematica of the form PersonSymbol. Thus, for example, the Legendre polynomials are denoted LegendreP[n, x]. Although this convention does lead to longer function names, it avoids any ambiguity or confusion.
When the standard notation for a mathematical function involves both subscripts and superscripts, the subscripts are given before the superscripts in the Mathematica form. Thus, for example, the associated Legendre polynomials are denoted LegendreP[n, m, x].