vniquify(expressionlist) → expressionlist
The subroutine vniquify takes an array of expressions as argument, sorts the expressions, and returns an array in which all duplicates have been removed. The items not removed occur in sorted order.
Call: uniquify(['c','b','c','b','a'])
Exit: [a,b,c]
Call: grindem(uniquify([read('p(b,c)'),read('p(a,b)'),read('p(a,b)')]))
Exit: p(a,b)
p(b,c)
vniquify runs in n*log n time. Compare to uniquify and zniquify.
