FUNCTION ISPLNK:INTEGER; EXTERNAL;
CONSTANT SERVIS='LMOPEN ';
         OPTION='INPUT  ';

VAR      LASTRC:INTEGER;
         DATAID:STRING(8);

BEGIN
⋮
LASTRC:=ISPLNK(SERVIS,DATAID,OPTION);

For functions written in Pascal, arguments can also be passed as variables or as literals.