; Returns the value that results from: ; item1 OP item2 OP .... itemN, evaluated left to right: ; ((item1 OP item2) OP item3) OP ... ; You may assume the list is a flat list that has at least ; one element. ; OP - the operation to be performed ; (accumulate '(1 2 3 4) (lambda (x y) (+ x y))) --> 10 ; (accumulate '(1 2 3 4) (lambda (x y) (* x y))) --> 24 ; (accumulate '(1) (lambda (x y) (+ x y))) --> 1 (define (accumulate lst OP)