$ swipl -l fibonacci.prolog
Welcome to SWI-Prolog (threaded, 64 bits, version 9.2.8)
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software.
Please run ?- license. for legal details.

For online help and background, visit https://www.swi-prolog.org
For built-in help, use ?- help(Topic). or ?- apropos(Word).

?- f(10,N).
N = 55.

?- f(20,N).
N = 6765.

?- f(30,N).
N = 832040.

?- f(40,N).
N = 102334155.

?- f(50,N).
^CAction (h for help) ? abort
% Execution Aborted
?- 

$ swipl -l class12.prolog
Welcome to SWI-Prolog (threaded, 64 bits, version 9.2.8)
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software.
Please run ?- license. for legal details.

For online help and background, visit https://www.swi-prolog.org
For built-in help, use ?- help(Topic). or ?- apropos(Word).

?- f(10,N).
N = 55.

?- f(20,N).
N = 6765.

?- f(30,N).
N = 832040.

?- f(40,N).
N = 102334155.

?- listing(t).
:- dynamic t/2.

t(0, 0).
t(1, 1).
t(2, 1).
t(3, 2).
t(4, 3).
t(5, 5).
t(6, 8).
t(7, 13).
t(8, 21).
t(9, 34).
t(10, 55).
t(11, 89).
t(12, 144).
t(13, 233).
t(14, 377).
t(15, 610).
t(16, 987).
t(17, 1597).
t(18, 2584).
t(19, 4181).
t(20, 6765).
t(21, 10946).
t(22, 17711).
t(23, 28657).
t(24, 46368).
t(25, 75025).
t(26, 121393).
t(27, 196418).
t(28, 317811).
t(29, 514229).
t(30, 832040).
t(31, 1346269).
t(32, 2178309).
t(33, 3524578).
t(34, 5702887).
t(35, 9227465).
t(36, 14930352).
t(37, 24157817).
t(38, 39088169).
t(39, 63245986).

true.

?- f(50,N).
N = 12586269025.