To make new lazy lists from old ones:

<memoized-cons> ( cons -- memoized-cons )

lappend-lazy ( list1 list2 -- result )

lconcat ( list -- result )

lcartesian-product ( list1 list2 -- result )

lcartesian-product* ( lists -- result )

lmerge ( list1 list2 -- result )

ltake ( list n -- result )

lzip ( list1 list2 -- result )