For example, there is the as the generalized eigenvalue problem 27#27, where A and B are given square matrices and we want to find the eigenvalue 28#28 and eigenvector x, and the singular value decomposition, which can be described as finding the eigenvalues and eigenvectors of 29#29 and 30#30.

The matrix-multiplication subroutine in the CM-2 Scientific Subroutine Library took approximately 10 person-years of effort to write [16].