SCHEME: Remove sub-lists
'((("a" "c") ("a" "l")) (("b" "c") ("b" "l")) (("c" "hmm")))

'(("a" "c") ("a" "l") ("b" "c") ("b" "l") ("c" "hmm"))

'("a" "c" "a" "l" "b" "c" "b" "l" "c" "hmm")

'(("a" "c") ("a" "l") ("b" "c") ("b" "l") ("c" "hmm"))

(define (flatten list)
   (cond ((null? list) '())
         ((list? (car list)) (append (flatten (car list)) (flatten (cdr list))))
         (else
          (cons (car list) (flatten (cdr list))))))

(define (createPairs a)
  (cond ((null? a) '())
        (else
         (cons (list (car a) (car (cdr a)))
               (createPairs (cdr (cdr a)))))))