Inferred syntax and semantics of PL/S
Gio C. M. Wiederhold, John R. Ehrman · 1971
This is an attempt to describe a language developed and used by IBM Corporation to support the writing of system programs. It is a PL/1-like language specifically oriented towards the kind of operations required In writing operating systems.The language was referred to originally as BSL, and is now called PL/S. By March 1971 development had proceeded to a version numbered 12.11. I t is this and shortly preceding versions that are described here.