【正确答案】LIBRARY IEEE;
   USE IEEE. STD_LOGIC_1164.ALL;
   ENTITY example IS
   PORT(  a: IN STD_LOGIC;
          b: IN STD LOGIC;
          c: IN STD LOGIC;
          y: OUT STD_LOGIC);
   END example；
   ARCHITECTURE arch OF example IS
   BEGIN
   y＜=a and (b or c);
   END arch;