| | Some definitions of interest. |
|
| int_seg | Def {i..j } == {k: | i  k < j } |
| | | Thm*  m,n:. {m..n}  Type |
|
| permute_list | Def (L o f) == mklist(||L||; i.L[(f(i))]) |
| | | Thm* T:Type, L:T List, f:( ||L||  ||L||). (L o f) T List |
|
| length | Def ||as|| == Case of as; nil  0 ; a.as' ||as'||+1 (recursive) |
| | | Thm* A:Type, l:A List. ||l|| |
| | | Thm* ||nil|| |
|
| mklist | Def mklist(n;f) == primrec(n;nil;i,l. l @ [(f(i))]) |
| | | Thm* T:Type, n:, f:(nT). mklist(n;f) T List |
|
| nat | Def == {i:| 0i } |
| | | Thm* Type |
|
| select | Def l[i] == hd(nth_tl(i;l)) |
| | | Thm* A:Type, l:A List, n:. 0n   n<||l|| l[n] A |
