prog.pas: In main program:
prog.pas:9: error: undeclared identifier `aa' (first use in this routine)
prog.pas:9: error: (Each undeclared identifier is reported only once
prog.pas:9: error: for each routine it appears in.)
prog.pas:9: error: undeclared identifier `bb' (first use in this routine)
prog.pas:10: error: syntax error before `mod'