| | 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 |
|
| firstn | Def firstn(n;as) == Case of as; nil nil ; a.as' if 0 <  n [a / firstn(n-1;as')] else nil fi (recursive) |
| | | Thm* A:Type, as:A List, n: . firstn(n;as) A List |
|
| int_iseg | Def {i...j} == {k:| i k & kj } |
| | | Thm* i,j:. {i...j} Type |
|
| length | Def ||as|| == Case of as; nil 0 ; a.as' ||as'||+1 (recursive) |
| | | Thm* A:Type, l:A List. ||l|| |
| | | Thm* ||nil|| |
|
| nth_tl | Def nth_tl(n;as) == if n0 as else nth_tl(n-1;tl(as)) fi (recursive) |
| | | Thm* A:Type, as:A List, i:. nth_tl(i;as) A List |
|
| top | Def Top == Void given Void |
| | | Thm* Top Type |
