/usr/lib/dag questions

[bill]

I noticed an executable file in /usr/lib of our SYS V's called 'dag'
that wasn't in the manuals. Maybe this stands for Data Access Graph?
It seems to read c programs from stdin and reports to stdout the last
values assigned to variables by the program by some ordering.
The only option I could find was a -d# where # is a number, but this
didn't alter the behavior of the program in any apparent way.

Does anyone know what /usr/lib/dag does? Can an ordinary user be able
to put it to any use?

We only have Binary licenses; the machines are NCR Towers.