Ann; SWI-Prolog 8.3.19

[peter.ludemann]

@EricGT

Perhaps the version of Prolog just before this should be archived for historical purposes because once => starts to creep in I think many who are not up with the current code will be lost when looking at the new code using =>

Or just look at this:

MODIFIED: Use SSU rules for some of the library(lists) predicates: