void          extract_thin_linkage(Sentence sent, Parse_Options opts, Linkage linkage);
void          extract_fat_linkage (Sentence sent, Parse_Options opts, Linkage linkage);
Linkage_info  analyze_fat_linkage (Sentence sent, Parse_Options opts, int pass);
Linkage_info  analyze_thin_linkage(Sentence sent, Parse_Options opts, int pass);