// Sample Code
module main( stb, a );
input stb;
output [1:0] a;
wire [1:0] b;
buf (a[0], b[0]);
buf (a[1], b[1]);
specify
(posedge stb => (a[0]:1'bx)) = 1.0;
(posedge stb => (a[1]:1'bx)) = 1.0;
endspecify
endmodule // main