The following definitions and conventions apply throughout this section:
| f | A function, or an operator's left operand (function or array). |
| g | A function, or an operator's right operand (function or array). |
| A | An operator's left argument when an array. |
| B | An operator's right argument when an array. |
| X | The left argument of a function. |
| Y | The right argument of a function. |
| R | The explicit result of a function. |
| [K] | Axis specification. |
| [I] | Index specification. |
| {X} | The left argument of a function is optional. |
| {R}← | The function may or may not return a result, or the result may be suppressed. |
function may refer to a primitive function, a system function, a defined (canonical, dfn or assigned) function or a derived (from an operator) function.