湖北大学2004-2005学年度第二学期课程考试试题纸(第2页共4页) =. Solve the following problems. (each 10 points, total 50 points) Find the disjunctive normal form and the conjunctive normal form which are logically equivalent to(p<>q) 2. Find a statement form involving only i which is logically equivalent to(p-q) 3. Determine whether the argument form(p(vr)),(r);.((9)(p) is valid or 说明:本试卷将作为样卷直接制版胶印,请命题教师在试题之间留足答题空间湖北大学 2004—2005 学年度第二学期课程考试 试题纸（第 2 页 共 4 页） 说明： 本试卷将作为样卷直接制版胶印，请命题教师在试题之间留足答题空间。 二. Solve the following problems. (each 10 points, total 50 points) 1. Find the disjunctive normal form and the conjunctive normal form which are logically equivalent to (p  q). 2. Find a statement form involving only ↓ which is logically equivalent to (p→q). 3. Determine whether the argument form (p→ (q∨r))，(～r); ∴ ((～q)→(～p)) is valid or invalid. 得 分