module Q4(A, En, Z);

input [2:0] A;

input En;

output reg [0:3] Z;

always@ (En, A)

case ({En, A})

4: Z = 4’h8; 

5: Z = 4’h4;

6: Z = 4’h2;

7: Z = 4’h1;

default: Z = 4’h0;

endcase

endmodule

If -> Then; _Else :- If, !, Then.

If -> _Then; Else :- !, Else.

If -> Then :- If, !, Then.

( condition -> then_clause ; else_clause )