Naming Conventions

Cortex follows the naming convention already used throughout MathJSON and the Compute Engine's library: capitalized identifiers denote library or engine operators, lowercase identifiers denote user-defined variables and functions.

Sin(x)
Simplify(2 + 3x^3)
Map([1, 2, 3], x |-> x^2)

Sin, Simplify, and Map are library operators; x is an ordinary user symbol.

This is a convention with no enforced semantics — nothing in the parser or the engine requires a capitalized name to be an operator or a lowercase name to be a variable. A user can declare a lowercase function or a capitalized variable; it will work exactly the same way. The convention exists so that, by scanning a program, it's usually obvious at a glance which names come from the library and which are the author's own.

Because the convention isn't enforced, a name collision — a user symbol that happens to share a capitalized library name, or vice versa — isn't a parse error. It resolves the same way any other symbol lookup does: by scope, not by case. A local declaration shadows an outer one (including a library operator) for the rest of that scope, exactly as it would for any other symbol.