DIRECTED GRAPH TESTS

 Test Case 1

```?- graph([[a,b],[[a,b],[b,c],[c,a],[b,a],[c,b]]]).
```

No

```?- graph([[a,b,c],[[a,b],[b,c],[c,a],[b,a],[c,b]]]).
```

Yes

```?- assert(defined_graph([[a,b,c],[[a,b],[b,c],[c,a],[b,a],[c,b]]])).
```

Yes

```?- defined_graph(X).
```

X = [[a,b,c],[[a,b],[b,c],[c,a],[b,a],[c,b]]] ;

No

```?- defined_graph(X), node(Y,X).
```

X = [[a,b,c],[[a,b],[b,c],[c,a],[b,a],[c,b]]]

Y = a ;

X = [[a,b,c],[[a,b],[b,c],[c,a],[b,a],[c,b]]]

Y = b ;

X = [[a,b,c],[[a,b],[b,c],[c,a],[b,a],[c,b]]]

Y = c ;

No

```?- defined_graph(X), arc([c,d],X).
```

No

```?- defined_graph(X), arc([c,b],X).
```

X = [[a,b,c],[[a,b],[b,c],[c,a],[b,a],[c,b]]] ;

No

```?- defined_graph(X), path(a,c,X).
```

Yes

```?- defined_graph(X), path(a,c,X,2)
```

Yes

```?- defined_graph(X), path(c,c,X).
```

Yes

```?- defined_graph(X), path(c,d,X).
```

No

```?- defined_graph(X), hascycle(X,3).
```

Yes

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Last modified: October 30, 2000, 07:55:05 EST, by Lenwood S. Heath <heath@cs.vt.edu>