Query version information. This function may be called before
If the key is unknown the function returns 0. See section
2.22 for a more in-depth discussion on binary compatibility.
Versions upto SWI-Prolog 8.5.2 defined this function as PL_version().
It was renamed to avoid a conflict with Perl affecting
PL_version() is provided as a macro for compatibility. Defined
SWI-Prolog version as 10,000 × major + 100 × minor +
Incremented if the foreign interface defined in this chapter changes in
a way that breaks backward compatibility.