| | Some definitions of interest. |
|
| append | Def as @ bs == Case of as; nil  bs ; a.as' [a / (as' @ bs)] (recursive) |
| | | Thm*  T:Type, as,bs:T List. (as @ bs)  T List |
|
| iff | Def P   Q == (P  Q) & (P Q) |
| | | Thm* A,B:Prop. (A B) Prop |
|
| l_before | Def x before y l == [x; y]  l |
| | | Thm* T:Type, l:T List, x,y:T. x before y l Prop |
|
| l_member | Def (x l) ==  i: . i < ||l|| & x = l[i] T |
| | | Thm* T:Type, x:T, l:T List. (x l) Prop |
|
| sublist | Def L1 L2 == f:(||L1||  ||L2||). increasing(f;||L1||) & (j:||L1||. L1[j] = L2[(f(j))] T) |
| | | Thm* T:Type, L1,L2:T List. L1 L2 Prop |
