Editing RPL (programming language) (section)

==Variants==
The internal low- to medium-level variant of RPL, called '''[[HP 49 series#Programming|System RPL]]''' (or '''SysRPL''') is used on some earlier HP calculators as well as the aforementioned ones, as part of their [[operating system]] implementation language. In the HP&nbsp;48 series this variant of RPL is not accessible to the calculator user without the use of external tools, but in the HP&nbsp;49/50 series there is a compiler built into ROM to use SysRPL. It is possible to cause a serious crash while coding in SysRPL, so caution must be used while using it. The high-level '''User RPL''' (or '''UserRPL''') version of the language is available on said graphing calculators for developing textual as well as graphical application programs. All UserRPL programs are internally represented as SysRPL programs, but use only a safe subset of the available SysRPL commands. The error checking that is a part of UserRPL commands, however, makes UserRPL programs noticeably slower than equivalent SysRPL programs. The UserRPL command SYSEVAL tells the calculator to process designated parts of a UserRPL program as SysRPL code.