| | Some definitions of interest. |
|
| edge | Def x-the_graph- > y ==  e:Edges(the_graph). Incidence(the_graph)(e) = < x,y > |
| | | Thm* For any graph
 x,y:V. x-the_graph- > y  Prop |
|
| ge | Def i j == j i |
| | | Thm* i,j: . (ij) Prop |
|
| gr_v | Def Vertices(t) == 1of(t) |
| | | Thm* t:Graph. Vertices(t) Type |
|
| graph | Def Graph == v:Type e:Type(e  vv)Top |
| | | Thm* Graph Type{i'} |
|
| int_seg | Def {i..j } == {k:| i k < j } |
| | | Thm* m,n:. {m..n} Type |
|
| length | Def ||as|| == Case of as; nil  0 ; a.as' ||as'||+1 (recursive) |
| | | Thm* A:Type, l:A List. ||l|| |
| | | Thm* ||nil|| |
|
| select | Def l[i] == hd(nth_tl(i;l)) |
| | | Thm* A:Type, l:A List, n:. 0n   n < ||l|| l[n] A |
|
| tl | Def tl(l) == Case of l; nil nil ; h.t t |
| | | Thm* A:Type, l:A List. tl(l) A List |
