Further to the previous message about a problem with sets in the cygwin version. The following program causes the compiler to crash in construct_set. The crash does not occur if the set definition is directly in the program rather than imported. The crash occurs whether the interface is in the same or separate files. # 1 "/Orion/pas/creatvar.pas" module data1 interface; export data1_interface = (usage1); type usage1 = (sysusage,sysgen,syscopy,master); end. module creatvar; export creatvar_int = (create_var); import data1_interface; procedure create_var(use1:usage1);C; end; procedure create_var; var i,j,k,l:integer; begin if not (use1 in [syscopy,sysgen]) {<<<<<<<<<-------<} then begin end; end; end. In addition, the module abc interface; end. module abc implementation; end. style of unit seems to have problems in carrying simple definitions forward, whereas the alternative style module does not. Regards Jim Brander