fold-left

(fold-left f initial list1 list2 ...)

Combines the elements of the lists from the left: (f (f (f initial e1) e2) e3). With several lists f takes the result so far and then one element of each, and the fold stops at the end of the shortest list. A Structure and Interpretation of Computer Programs (SICP)/MIT name, not R7RS: no library exports it, so it is visible only to a file with no import and at the REPL.