contfrac(1,[],-1)
v=[1,2,3];
contfracpnqn(v)
contfracpnqn(v,0)
contfracpnqn(v,2)
v=[1,2,3;4,5,6];
contfracpnqn(v)
contfracpnqn(v,0)
contfracpnqn(v,2)
