read_verilog -sv initval.v
proc;;

sat -seq 10 -prove-asserts

design -reset
read_verilog -icells <<EOT
module top(input clk, i, output [1:0] o);
(* init = 2'bx0 *)
wire [1:0] o;
assign o[1] = o[0];
$_DFF_P_ dff (.C(clk), .D(i), .Q(o[0]));
endmodule
EOT
sat -seq 1