Cannot import name 'ForAll' from 'lnn'

[daisylab]

Hi, I'm currently studying the LNN, and trying to evaluate the example code.

However, I've got this error from the example code:

1. example code:

https://ibm.github.io/LNN/education/examples/reasoning.html#simple-geometry-reasoning-example

2. where I stuck:

Python 3.10.6 (main, Nov 14 2022, 16:10:14) [GCC 11.3.0]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.11.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: from lnn import (Predicate, Variable,
   ...:                  Exists, Implies, ForAll, Model, Fact, World)
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
Cell In[1], line 1
----> 1 from lnn import (Predicate, Variable,
      2                  Exists, Implies, ForAll, Model, Fact, World)

ImportError: cannot import name 'ForAll' from 'lnn' (/home/sungjin/.virtualenvs/lnn/lib/python3.10/site-packages/lnn/__init__.py)

I know that LNN is a great tool which will leverage the next step of AI, and I glad to know about it. And I hope there will be a chance to the newcomers like me. Thank you.

[daisylab]

Oh, I figured it out why it does not work. ForAll is changed to Forall, the 'a' in the name is no longer capital.

In [1]: from lnn import ForAll
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
Cell In[1], line 1
----> 1 from lnn import ForAll

ImportError: cannot import name 'ForAll' from 'lnn' (/home/sungjin/.virtualenvs/lnn/lib/python3.10/site-packages/lnn/__init__.py)

In [2]: from lnn import Forall

In [3]: 

however, I got another error, that is,

from lnn import (Predicate, Variable,
                 Exists, Implies, Forall, Model, Fact, World)

model = Model()

# Variable
x = Variable('x')

# Predicate declarations
square = Predicate('square')
rectangle = Predicate('rectangle')
foursides = Predicate('foursides')

# Axioms declarations
square_rect = Forall(x, Implies(square(x), rectangle(x)))
rect_foursides = Forall(x, Implies(rectangle(x), foursides(x)))

# Query

query = Exists(x, foursides(x))

# Add predicates and rules to the model
model.add_knowledge(square, rectangle, square_rect, rect_foursides, query)

# Add facts to the model
model.add_data({square: {'c': Fact.TRUE, 'k': Fact.TRUE}})

# Perform inference
steps, facts_inferred = model.infer()

# Inspect the query node
# print(model['foursided_objects'].true_groundings)
print(model[query].true_groundings)

which is expected to emit the result:

 {'c', 'k'} 

but it just says:

(lnn) sungjin@daisylab:~/home/lnn-examples> python simple.py
set()