-- The structures are determined by symbfact_dist and not used thereafter.
(xlsub,lsub): lsub[*] contains the compressed subscript of L, as described above for Pslu_freeable_t. This structure is used internally in symbfact_dist. (xusub,usub): usub[*] contains the compressed subscript of U, as described above for Pslu_freeable_t. This structure is used internally in symbfact_dist.
(xlsubPr,lsubPr): contains the pruned structure of the graph of L, stored by rows as a linked list. xlsubPr[j] points to the starting location of the j-th row in lsub[*]. Storage: original row subscripts. It contains the structure corresponding to one node in the sep_tree. In each independent domain formed by x vertices, xlsubPr is of size x. Allocated and freed during domain_symbolic. For the other nodes in the level tree, formed by a maximum of maxNvtcsNds_loc, xlsubPr is of size maxNvtcsNds_loc. Allocated after domain_symbolic, freed at the end of symbolic_dist routine. (xusubPr,usubPr): contains the pruned structure of the graph of U, stored by columns as a linked list. Similar to (xlsubPr,lsubPr), except that it is column oriented.
This is allocated during symbolic factorization symbfact_dist.