The mzlib/list library re-exports several functions
from scheme/base and scheme/list:
Accesses the first, second, etc. elment of “list” v
argument need not actually be a list; it is inspected only as far as
necessary to obtain an element (unlike the same-named functions from
, which do require the argument to be a
Returns the last pair in v, raising an error if v is
not a pair (but v does not have to be a proper list).
Merges the two sorted input lists, creating a new sorted list. The
merged result is stable: equal items in both lists stay in the same
order, and these in lst1 precede lst2.