[R] function name collision

[Bobby Prill]

I am using the "graph" package, which has a function called union()  
that acts on graph objects.  There is also a {base} function called  
union().  How do I explicitly specify union {graph} instead of the  
default union {base} ?

union(g1, g2)   evokes the wrong union(), which produces an error.

Thanks for the help.
- Bobby