To provide a finite element method library for avoiding a calculation error due to a program preparation mistake and deterioration of convergence time by improving the reliability of a program that utilizes a finite element method as a library.

This library describes program processing by a finite element method and defines a vector in a vector space in which a basis function of the finite element method is stretched and a dual vector in a dual space defined by measurement introduced by an inner product decided from a square integral of the basis function as different abstract data types.