PoS
p = PoS(x, z);
p = v + PoS(v, t);
w = PIO2_L + PoS(x, z);
w = PI_L + PoS(x, z);
w = PoS(x, z) - PI3O2_L;
w = PoS(x, z) - PI2_L;
w = PI5O2_L + PoS(x, z);