x:T, l1,l2:T List. (x 
l1 @ l2) 
(x l1) 
(x l2)l:T List, a,x:T. (x [a / l]) x = a (x l)| Rank | Theorem | Name |
| 2 | x:T, l1,l2:T List. (x l1 @ l2) (x l1) (x l2) | [member_append] |
| cites the following: | ||
| 1 | l:T List, a,x:T. (x [a / l]) x = a (x l) | [cons_member] |