How troubleshoot ERROR: toplevel: Undefined procedure ?!

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Hello, I Follow: Knowledge Processing For Autonomous Robot

I write a simple knowledge base as a test.pl in prolog file, in my package then I try to query it

prolog -f test.pl

and I get a top level error !

?- cup(cup0).
ERROR: toplevel: Undefined procedure: cup/1 (DWIM could not correct goal)

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amal@amal-HP-G62-Notebook-PC:~$ prolog -f test.pl
Welcome to SWI-Prolog (Multi-threaded, 32 bits, Version 5.10.4)
Copyright (c) 1990-2011 University of Amsterdam, VU Amsterdam
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to redistribute it under certain conditions.
Please visit http://www.swi-prolog.org for details.

For help, use ?- help(Topic). or ?- apropos(Word).

?- cup(cup0).
ERROR: toplevel: Undefined procedure: cup/1 (DWIM could not correct goal)
?-

and that is what in test.pl

cup(cup0).
dairyProduct(milk1).
meatProduct(ham2).
cupboard(cupboard3).
refrigerator(fridge4).
perishable(Prod)            :- dairyProduct(Prod), meatProduct(Prod).
storagePlaceFor(Loc, Item)  :- refrigerator(Loc), perishable(Item).
storagePlaceFor(Loc, Item)  :- cupboard(Loc), cup(Item).
searchForIn(Item,Loc)       :- storagePlaceFor(Loc, Item).

any suggestion ?!

Thanks.