I have a question that says write a procedure that takes a random graph and three edges of that graph and returns true if those edges share a common vertex. So I was thinking of something along the lines of

proc55 := proc (G, {a, b}, {c, d})

if evalb({a, b} = {a, c} or {a, b} = {a, d} or {a, b} = {b, c} or {a, b} = {b, d}) then print(true)

else print(false)

end if;

end proc;

I guess my main question is how do I put edges in the parameters line? It will let me write proc (G, a, b, c, d) but not proc (G, {a, b}, {c, d}).

Is there just something I'm missing or am I approaching this in the wrong way?