Informal negotiations over how to expand the Pell Grant to job-training programs have begun but lawmakers face uphill challenge in getting a bill through Congress. With three different bills proposed that would allow students to use the Pell Grant for short-term programs of fewer than 15 weeks, the current minimum, momentum is building on the issue, and House lawmakers are beginning to talk about it informally. But muscling any legislation through this Congress will be difficult, advocates and lobbyists say.