The physical part of the inventive process that completes the process of invention. Until there is a reduction of practice, there is no invention. There are two kinds of reduction of practice: 1)

Constructive reduction to practice occurs upon the filing of a U. S. patent application that adequately discloses the invention. Constructive reduction to practice does not involve any physical construction. 2) Actual reduction to practice occurs when there is physical verification that the invention works for the intended purpose. The reduction to practice must involve each and every element that is defined as constituting the invention. The degree of physical verification required will depend on the nature and complexity of the invention.