| | Some definitions of interest. |
|
| connect | Def x-the_graph- > *y ==  p:Vertices(the_graph) List. path(the_graph;p) & p[0] = x & last(p) = y |
| | | Thm* For any graph
 x,y:V. x-the_graph- > *y  Prop |
|
| decidable | Def Dec(P) == P   P |
| | | Thm* A:Prop. Dec(A) Prop |
|
| 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 |
|
| 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'} |
|
| iff | Def P   Q == (P  Q) & (P Q) |
| | | Thm* A,B:Prop. (A B) Prop |
|
| not | Def A == A False |
| | | Thm* A:Prop. (A) Prop |
