Minor cosmetic change, added one space in vertical lists
Improved ,NL, to allow using it in the tail of a list
Avoiding errors when Pos is a free variable
Recovered predicate deleted by mistake
In ref_expand.pl, Now File can be unified in Expander
Improved '$C'/2 hook
Updating operators
Using remove_dups instead of sort, to preserve order
Less fail-prone line_pos/1.  Added hack '' to ignore Pattern layout
Removed gtrace
Minor kludge to avoid side modifications of refactor_text