Question

7. Suppose that the equal 1ists function (page 49 of Sebesta) is called with the lists ((A (B)) (C) ) and ((A (B)) (C)) as the arguments. How many calls of equal lists will be performed altogether, including the original call and all recur- sive calls? The following is an example of a Lisp program: Lisp Example function The following code defines a Lisp predicate function that takes two lists as arguments and returns True ;if the two lists are equal, and NIL (false) otherwise (DEFUN equal lists (lisl lis2) (COND C (ATOM lis1) (EQ lisl lis2) ) ((ATOM lis2) NIL) (lequal lists (CAR lis1) (CAR 1is2)) (equal lists (CDR 1is1) (CDR lis2))) (T NIL)

Answer 1

Solulin will e6usn NIL thisis the Sunction A. ive tuo ists ae not equal the be cause NE Thede ate Callst fox the egual 5 B. 600 fs ofigl Junction amahich lists decutsive Calls others 4afe Call and Call is ofig:nal dne fos oual. listsAA Will be Call than ano ther Call s done. Since it s 6ue and Caual sts (next elemené next lement (A)) equal lists (B,8) Calls Agato MON cqual lists (8.8) and all. it is Gtue i Since ano the nake s cs Scanned with CamScanner

(nexeelement (B). nextelementlB) qual lists eual lists CC.D). alls and r eual-st Cc.D) nce itis Jalse no moye RE tebusns NIA )Sen dome and be alls wil 110 N1 N to 11ps oih ((A A t C30 0 CS Scanned with CamScanner