Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.



Task

Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.



See also

 Wikipedia article:   Fold
 Wikipedia article:   Catamorphism


reduce f lst init:
	if lst:
		f reduce @f lst init pop-from lst
	else:
		init
 
!. reduce @+ [ 1 10 200 ] 4
!. reduce @- [ 1 10 200 ] 4
 