top_tf.v

module top;
    task foo;
        $display("task foo() called");
    endtask
    function bar;
        input [2:0] n;
        bar = baz(n + 1);
    endfunction
    function baz;
        input [2:0] n;
        baz = n * 2;
    endfunction
    localparam PARAM = 37;
    initial foo();
    initial $display("bar(0) = %d", bar(0));
    initial $display("PARAM = %d", PARAM);
endmodule