prolog第一个程序

PREDICATES
student(integer,string,real)
grade
GOAL
grade.
CLAUSES
student(1,"张三",90.2).
student(2,"李四",90.2).
student(1,"王五",90.2).
grade:-write("请输入姓名:"),readln(Name),
student(_,Name,Score),
nl,write(Name,"的成绩是",Score).
grade:-write("对不起,找不到这个学生!").