eTo(x_to_client(xys[0][0]), y_to_client(xys[0][1]));
            context.lineTo(x_to_client(xys[1][0]), y_to_client(xys[1][1]));
            context.strokeStyle = line_colors[solver_1_eq_temp_id - 1];
            context.setLineDash([4, 4]);
            context.stroke();
            context.setLineDash([]);
            context.closePath();
            
        }else if(document.getElementById("button_2").disabled){
            context.beginPath();
            context.setLineDash([4, 4]);
            context