QZ algorithm

An alternative method to solving Equation 12.3 is to reduce both Rj and R2 to square, nonsingular, nonidentity matrices by projecting each matrix independently onto the space formed jointly by the two matrices. This permits calculation of A and F, via the QZ algorithm [23] and, by extension, relative concentration estimates, Z, and estimates of the true underlying factors in the X- and Y-ways. This is known as the generalized rank annihilation method (GRAM) [24, 25],... 

Algorithms are available to solve Equation (6.60), e.g, using the QZ algorithm [Golub ... 

Fokkema, D.R., Sleijpen, G.L.G., Vorst, H.A.v. Jacobi-Davidson style QR and QZ algorithms for the reduction of matrix pencils. SIAM Journal on Scientific Computing 20(1), 94-125 (1999)... 

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