UFH Variables and Value Types
| Double | a double-precision floating-point value |
| String | a sequence of ASCII characters; internally stored as a null-terminated array of characters |
| Stream | a pointer to an input or output stream; returned or used by I/O functions |
| LineHeader | a USP line header object [includes the historical line header] |
| Trace | a USP trace object; consists of a trace header and a trace time series |
| Nothing | a special type for which the only legal value is itself; used to flag uninitialized variables and to clear memory during execution |
| Array | an array of any legal types [including arrays] |
| fVector | a special type of array holding only numeric values; internally stored as single-precision floating-point values |