digraph G {
    margin=0;
    f [style=bold, label="file-01"];
	
    i [label=<<FONT COLOR="red">S</FONT>>,fontname=helvetica];
	p [label=<<FONT COLOR="red">O</FONT>>,fontname=helvetica];
    b [label="before"];  
	
    r [label="read-01"];
    


    f->i [label="ARG0"];
    f->p [label="ARG1"];
    f->b [label="time"];
    i->r [label="ARG0", dir=back];
    p->r [label="ARG1", dir=back];
    b->r [label="op1"];
}