$fs = 0.4;
$fa = 1;

module base_shape() {
    text("hello");
}

module mirror_duplicate(axis) {
    children();
    mirror(axis) children();
}

minkowski() {
    linear_extrude(1) base_shape();
    mirror_duplicate([0, 0, 1]) cylinder(r1=0.2, r2=0, h=0.2);
}