Within the first five minutes of Ahmed Naumaan’s “Denial of Service,” one character warns another: “Get ready for a philosophical disquisition.” She’s not kidding. Most of this earnest but clumsily didactic piece focuses on three students (Ankita Ashrit, Taylor Meyer and Jessica Passaro) debating a range of lightning-rod subjects, including immigration, Trump’s travel ban, the Walker’s “Scaffold” sculpture. In between astonishingly pedantic arguments, they commiserate with a fourth student (Bao Vue) whose boyfriend has been detained by ICE. Add in mechanical staging and a ponderous pace and this work is less a drama than a lecture. (8:30 p.m. Sun., 7 p.m. Thu., 10 p.m. Sat. Aug. 12, 5:30 p.m. Sun. Aug. 13, Rarig Center Xperimental, 330 21st Av. S., Mpls.)