static public void output(Writer out, Node s, Node p, Node o, Node g, Prologue prologue, NodeToLabel labelPolicy) { output(out, s, prologue, labelPolicy) ; print(out," ") ; output(out, p, prologue, labelPolicy) ; print(out," ") ; output(out, o, prologue, labelPolicy) ; if ( g != null ) { print(out," ") ; output(out, g, prologue, labelPolicy) ; } print(out," .") ; println(out) ; }