The JACOBIAN statement defines the JACOBIAN matrix J for a system of objective functions. For more information, see the section "Derivatives". proc nlp tech=levmar; array j[2,2] j1-j4; lsq f1 f2; ...

In this paper we prove global univalence results in $R^{4}$ when the Jacobian matrices are of the Leontief type. Proofs of these make use of ideas from Gale-Nikaido ...