a number representing the ordinal sorted position of the target array, so if AMERICA is the sixth element of array but first in alphabetical order, then setting would cause to contain the value 1. Writing a BASIC program is much more fun than rewriting the same program each time you use it, therefore the authors of BASIC allow programmers to their program code to a library member and to it when changes are made. causes the current module to be saved as a subroutine member (type R) named in a user library named . Note that System/36 files are not part of libraries. If a disk file is named , then an statement like this one can work: It doesn't matter which library is used to access file FNF001. is the S/36 BASIC command used to renumber statements. All internal references to statement numbers are immediately recalculated. System/36 BASIC has a very dangerous command called . Typing followed by a filename deletes that file without a trace. It will work for every user file, unless there is a conflict of security or an in-use condition that blocks it. System/36 BASIC has another dangerous command called . The command will make the current program source code inaccessible and it is not reversible. Always save an unlocked copy before using LOCK. Incompatibility Between S/34 and S/36 System/34 BASIC and System/36 BASIC are very similar; however, machine code incompatibility makes it impossible to port a subroutine member BASIC program between these systems. See also Square Root of 2 & PI π solution for solution published on mainframes during the 1980s & 1990s. References BASIC interpreters System 36 BASIC