fcn prettyPrint(m){ // m is a list of lists
   fmt:=("%3d "*m.len() + "\n").fmt;
   m.pump(String,'wrap(col){ fmt(col.xplode()) });
}
const N=5;
println("Upper:\n",    pascal_upp(N):prettyPrint(_));
println("Lower:\n",    pascal_low(N):prettyPrint(_));
println("Symmetric:\n",pascal_sym(N):prettyPrint(_));