[tasks]
btormc
smtbmc

[options]
mode cover
expect fail

[engines]
btormc: btor btormc
smtbmc: smtbmc

[script]
read -formal top.sv
prep -top top -flatten

[file top.sv]

module top(input clk);

    inner inner(clk);

endmodule

module inner(input clk);
    reg [7:0] counter = 0;

    always @(posedge clk) begin
        counter <= counter == 4 ? 0 : counter + 1;

        reachable: cover (counter == 3);
        unreachable: cover (counter == 5);
    end
endmodule