return isomorphism(G1, G2, f,

choose_param(get_param(params, vertex_invariant1_t()), invariant1),

choose_param(get_param(params, vertex_invariant2_t()), invariant2),

choose_param(get_param(params, vertex_max_invariant_t()), ( invariant2.max)()),

index_map1, index_map2

);

If "vertex_invariant1_t()" and "vertex_invariant2_t()" are both changed to "vertex_invariant_t()", the setting of the parameter then seems to have an affect. Has anyone been able to successfully set the vertex_invariant parameter using the named parameter version of the isomorphism function? I have had to resort to calling one of the internal isomorphism functions to set this parameter.

any help is appreciated,

Patrick