A dotted pair is not the same as an AutoLISP list (which is stored in memory as a
linked list).
When two atoms form a
cons cell, the second atom occupies the decrement register and is returned by the
cdr function, as opposed to the tail of the linked list. As such, when the
nth function attempts to traverse the list as a linked list, accessing any element except the first will result in an error as the
nth function is presented with an atom as opposed to the tail of the list.
Hence, to access the second element of a dotted pair, you would use the
cdr function in the following way:
Command: (cdr lst)
"test"