Farely fractions of level one is defined as sequence (0/1, 1/1). This sequence is extended in level two to form a sequence (0/1, ½, 1/1), sequence (0/1, 1/3, ½, 2/3, 1/1) at level three, sequence (0/1, ¼, 1/3, ½, 2/3, ¾, 1/1) at level four, so that at each level n, a new fraction (a+b) / (c+d) is inserted between two neighbour fractions a/c and b/d only if c+d <= n. Devise a procedure, which for a number n entered by the user creates – by constantly extending it – a linked list of fractions at level n.