logic-and-learning-lab/Popper

Error 'error(type_error(integer,...)` in v2.0.0

Closed this issue · 2 comments

hakank commented

I'm testing my old instances and got an error when running the following:

bias.pl (see below for a comment on the commented lines)

max_vars(5).
max_body(10).
max_clauses(2).

head_pred(f,2).
% type(f,(list,list)).
% direction(f,(in,out)).

body_pred(f,2).

body_pred(tail,2).
% type(tail,(list,list)).
% direction(tail,(in,out)).

body_pred(head,2).
% type(head,(list,element)).
% direction(head,(in,out)).

body_pred(last,2).
% type(last,(list,element)).
% direction(last,(in,out)).

body_pred(length,2).
% type(length,(list,int)).
% direction(length,(in,out)).

body_pred(sum,3).
% type(sum,(int,int,int)).
% direction(sum,(in,in,out)).

body_pred(cons,3).
% type(cons,(element,list,list)).
% direction(cons,(in,in,out)).

body_pred(empty,1).
% type(empty,(list,1)).
% direction(empty,(in,)).

body_pred(zero,1).
% type(zero,(int,)).
% direction(zero,(in,)).

bk.pl

cons(A,B,C):-
    append([A],B,C).
tail([_|T],T).
head([H|_],H).
sum(A,B,C):-
    C is A+B.
empty([]).
zero(0).

exs.pl

pos(f([65, 32, 87, 84, 25, 91, 36, 43, 64, 78, 51, 65, 90],[65, 32, 87, 84, 25, 91, 36, 43, 64, 78, 51, 65])).
pos(f([65, 32],[65])).
pos(f([1,2,3],[1,2])).
pos(f([65, 32,23],[65,32])).

neg(f([1,2,3],[1,2,3])).
neg(f([1,2,3],[1])).

Running the program:

$  time python3 popper.py --debug hakank/droplast
20:47:46 Max rules: 2
20:47:46 Max vars: 5
20:47:46 Max body: 10
20:47:46 Num. pos examples: 4
20:47:46 Num. neg examples: 2
Traceback (most recent call last):
  File "popper.py", line 8, in <module>
    prog, score, stats = learn_solution(settings)
  File "/home/hakank/inductive_programming/andrewcropper/popper/Popper/popper/loop.py", line 198, in learn_solution
    timeout(settings, popper, (settings,), timeout_duration=int(settings.timeout),)
  File "/home/hakank/inductive_programming/andrewcropper/popper/Popper/popper/util.py", line 65, in timeout
    result = func(*args, **kwargs)
  File "/home/hakank/inductive_programming/andrewcropper/popper/Popper/popper/loop.py", line 83, in popper
    pos_covered, inconsistent = tester.test_prog(prog)
  File "/home/hakank/inductive_programming/andrewcropper/popper/Popper/popper/tester.py", line 83, in test_prog
    pos_covered = frozenset(self.query('pos_covered(Xs)', 'Xs'))
  File "/home/hakank/inductive_programming/andrewcropper/popper/Popper/popper/tester.py", line 14, in query
    return set(next(self.prolog.query(query))[key])
  File "/usr/local/lib/python3.7/site-packages/pyswip/prolog.py", line 129, in __call__
    "Returned: '", str(term), "'."]))
pyswip.prolog.PrologError: Caused by: 'pos_covered(Xs)'. Returned: 'error(type_error(integer, [1, 2]), context(/(length, 2), _54))'.

Originally bias.pl contained the commented lines, but then Popper found this solution directly and then hanged. For some reason it didn't timeout after 10 minutes (I stopped it manually after 12 minutes).

20:20:36 New best hypothesis:
20:20:36 tp:1 fn:3 size:5
20:20:36 f(A,B):- cons(E,C,B),tail(D,C),head(A,E),tail(A,D).
20:20:36 ********************
20:20:36 Searching programs of size: 6

With the --debug flag it hangs here:

...
20:51:52 f(A,B):- cons(C,A,B),f(B,A),head(A,C).
20:51:52 Program 64:
20:51:52 f(A,B):- tail(A,B).
20:51:52 f(A,B):- last(A,C),f(B,A),cons(C,A,B).
20:51:52 Program 65:
20:51:52 f(A,B):- tail(A,B).
20:51:52 f(A,B):- f(B,A),tail(A,C),tail(C,B).
andrewcropper commented
  • 👍1
hakank commented

Thanks. After I fixed bias.pl this works as expected.