modify multiinsertL and multiinsertR Chap08 p143 L1
add multiinsertLR Chap08 p143 L2
add multiinsertLR&co Chap08 p144 L1
modify multiinsertLR&co Chap08 p145 L3
add evens-only* Chap08 p146 L4
add evens-only*&co Chap08 p147 L4
modify evens-only*&co Chap08 p148 L3
add the-last-friend and modify evens-only*&co Chap08 p148 L5