Article 22 of the Patent Act provides that, where an invention can be easily made by a person having ordinary skill in the art (PHOSITA) based on prior art, no invention patent shall be granted, notwithstanding the other requirements of patentability. From a literal interpretation of the provision, when an invention filed for a patent can be easily accomplished by a PHOSITA based on the prior art before filing, the invention will be regarded as lacking an inventive step over the prior art, even though it may be novel.