| ESSENTIAL ITERATORS | \/ |  On dyadic operators the items of the shorter are cyclicaly used
|  to match longer .

  `( 'm 'd 'L 'R ./ .\ Y./  '.. aaply aaplym )` 

 'm 	| each monadic 	| ( list ' verb -- verb applied to each item of list ) 
 'd 	| each dyadic 	| ( Left Right ' verb -- verb applied to each corresponding pair of items of 2 lists ) 
 'L	| each Left	| ( Left Right ' verb -- apply verb to each item of left to whole of Right )
 'R	| each Right	| ( Left Right ' verb -- apply verb to each item of Right to whole of Left )

 ./	| across 	| ( List ' verb -- apply verb across list , eg: | i( 1 2 3 )i ' +i ./ |>| 6 )
 Y./	| initial across | ( start list ' verb -- like /\ but with a starting list , eg , applying a sequence of edits to a text )
 .\	| scan		| like ` across , but returns sequential results as it goes , eg: | i( 1 2 3 )i ' +i .\ |>| 1 3 6 
 
 '.. 	| each pair	| ( List ' verb -- apply verb between each sequential pair -- like differentiation 

 aaply  | atomic apply  | ( Left Right ' verb -- apply verb to corresponding simple leafs of pair of lists 
 aaplym | atomic apply monadic | likewise over single list 

 on2 	| ( L R f -- apply f to each L and R ) | ` on2> , leave args on stack