arg1 invoked with argument;
arg2 {
    arg1 invoked with argument1;
    arg1 invoked with argument2;
}
arg3 {
    arg2 {
        arg1 invoked with x;
        arg1 invoked with y;
    }
    arg1 invoked with z;
}
nested;
toplevel was called with hallo and contains a;
nested;
first a1;
rest;
invisible $invisible;
block {
}
first He\ 'lo;
rest a2 He\ 'lo;
invisible $invisible;
block {
    arg1 invoked with He\ 'lo;
    no $nested_var here;
}