| | Who Cites edge? |
|
| 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_f | Def Incidence(t) == 1of(2of(2of(t))) |
| | | Thm* t:Graph. Incidence(t) Edges(t)  Vertices(t) Vertices(t) |
|
| gr_v | Def Vertices(t) == 1of(t) |
| | | Thm* t:Graph. Vertices(t) Type |
|
| gr_e | Def Edges(t) == 1of(2of(t)) |
| | | Thm* t:Graph. Edges(t) Type |
|
| pi2 | Def 2of(t) == t.2 |
| | | Thm* A:Type, B:(AType), p:(a:AB(a)). 2of(p) B(1of(p)) |
|
| pi1 | Def 1of(t) == t.1 |
| | | Thm* A:Type, B:(AType), p:(a:AB(a)). 1of(p) A |
