Segmentation fault when using numbers in clauses

[didac.b...@gmail.com]

Hi,

I'm new to pyswip (as well as in Prolog) and I'm having problems with using numbers in the clauses. 

Example:

from pyswip import Prolog

p = Prolog()

p.assertz("fact(a)")

p.assertz("fact(b)")

print list(p.query("fact(X)"))

This works fine, and it outputs, as expected:

[{'X': 'a'}, {'X': 'b'}]

However, if I add:

p.assertz("fact(3)")

print list(p.query("fact(X)"))

I then get a "Segmentation fault: 11"

Any idea of what is happening? Can I use numbers in clauses?