Penalty term when criterion="aic". Only k=2 gives
genuine AIC.
alpha
Critical value for deeming an edge to be significant/
insignificant. When criterion="aic", alpha defaults to
0; when criterion="test", alpha defaults to 0.05.
headlong
If TRUE then testing will stop once a model
improvement has been found.
details
Controls the level of printing on the screen.
…
Further arguments to be passed on to testdelete
(for testInEdges) and testadd (for testOutEdges).