What is the test for ineffective representation of counsel in a habeas corpus case?

A habeas corpus petitioner who challenges his conviction claiming ineffective assistance of counsel must demonstrate both that his attorney's representation was outside "the wide range of professionally competent assistance," and that this deficient legal representation prejudiced his defense. Strickland v. Washington, 466 U.S. 668, 687-690 (1984). To determine whether legal assistance was deficient, the court must inquire "whether counsel's assistance was reasonable considering all the circumstances" at the time of the assistance. Id. at 688. There is a strong presumption that counsel rendered adequate assistance. Id. at 689. To show prejudice, a petitioner must show "that there is a reasonable probability that, but for counsel's unprofessional errors, the result of the proceeding would have been different." Id. at 694.