S. 148A: Reassessment-Conducting inquiry, providing opportunity before issue of notice-Dropping of re-assessment proceedings after considering the reply-Issuing notice again taking contrary stand within span of five days-Notice and order is quashed-Strictures-Principal Chief Commissioner is directed to conduct an inquiry against concerned officer who had passed said two orders, which contradicted each other, in a span of five days and to take necessary action. [S. 148A(b), 148A(d),149, 151,Art. 226]