options nodate nonumber ps=55 ls=80; title 'RPD -- Example 2.6'; proc iml; A={1 2, 3 3, 5 7}; y={6,9,21}; GINV_A=ginv(A); x=GINV_A*y; print A; print y; print GINV_A; print x; AGINV_AA = A*GINV_A*A; print AGINV_AA; run;