| Some definitions of interest. |
|
iseg | Def l1 l2 == l:T List. l2 = (l1 @ l) |
| | Thm* T:Type, l1,l2:T List. l1 l2 Prop |
|
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 |