[procedure] pair-fold kons knil clist1 clist2 ...

SRFI-1: Analogous to fold, but kons is applied to successive sublists of the lists, rather than successive elements -- that is, kons is applied to the pairs making up the lists, giving this (tail) recursion:

     (pair-fold kons knil lis) = (let ((tail (cdr lis)))
                                   (pair-fold kons (kons lis knil) tail))
     (pair-fold kons knil '()) = knil

See also pair-fold-right.