function X=foldr(fn,e,args)
% foldr - Fold from the right combinator 
%
% foldr :: (Y,X->X),	Y, cells(Y) -> Y.
%
% This function applies an associative operator to a list of arguments,
% starting from the right, eg
% elements, eg foldr(@plus,0,{1,2,3,4}) = (1+(2+(3+(4+0)))).
X=e; for i=length(args):-1:1, X=fn(args{i},X); end
