7.110 bug in networks[connectivity], from Maple 6 to Maple 8 (19.11.01)

7.110.1 Edwin Clark

Apparently a bug was introduced when going from Maple V r5.1 to Maple 6 and retained in Maple 7 in networks[connectivity]

Here’s a simple example:

Consider the graph G defined below which clearly has connectivity (that is, edge-connectivity) 1:

> interface(version); 
 
  Maple Worksheet Interface, Maple 7.00, APPLE_PPC_MAC, Tue, May 2\ 
        9, 2001 Build ID 96223 
 
> restart: 
> with(networks): 
> V:={1,2,3,4,5, 6}: 
> E:={{1,2},{2,3}, {3,1}, {3,4}, {4,5}, {5,6}, {4,6}}: 
> G:=graph(V,E): 
> 
> connectivity(G, 1, s1), s1; 
 
                         2, {{5, 6}, {4, 5}}
 

On the other hand in Maple V r5.1 we get the correct answer:

> interface(version); 
 
  Maple Worksheet Interface, Release 5.1, APPLE_PPC_MAC, Aug 20 19\ 
        98 
 
> restart: 
> with(networks): 
> V:={1,2,3,4,5, 6}: 
> E:={{1,2},{2,3}, {3,1}, {3,4}, {4,5}, {5,6}, {4,6}}: 
> G:=graph(V,E): 
> 
> connectivity(G, 1, s1); s1; 
 
                                  1 
 
                               {{3, 4}}
 

The bug retained in Maple 8, too (U. Klein)