No, actually, I worked around that.

The only reason that PutLinkUTest currently passes is because PutLink fails
to treat ScopeLinks correctly.  When that gets fixed, the unit test will
fail ... the issue remains the same.

--linas

On Tue, Oct 11, 2016 at 11:57 PM, Nil Geisweiller <ngeis...@googlemail.com>
wrote:

> Are these unit tests still failing?
>
> Nil
>
>
> On 10/11/2016 08:36 PM, Linas Vepstas wrote:
>
>> 47 unit tests fail ... I'm not sure if they all fail for the same
>> reason, though.
>>
>> For example PutLink
>>
>> (PutLink
>>    (LambdaLink
>>      (VariableList
>>        (TypedVariableLink
>>          (VariableNode "$X")
>>          (TypeNode "PredicateNode")
>>        )
>>        (TypedVariableLink
>>          (VariableNode "$Y")
>>          (TypeNode "PredicateNode")
>>        )
>>      )
>>      (AndLink
>>        (EvaluationLink
>>          (PredicateNode "acquainted")
>>          (ListLink
>>            (VariableNode "$X")
>>            (VariableNode "$Y")
>>          )
>>        )
>>        (ImplicationLink
>>          (VariableNode "$X")  ; this is alpha-converted to $foo1233
>>          (PredicateNode "is-human")
>>        )
>>        (ImplicationLink
>>          (VariableNode "$X") ; this is alpha-converted  to $bar456
>>          (PredicateNode "is-human")
>>        )
>>      )
>>    )
>>    (ListLink
>>      (PredicateNode "is-Self")
>>      (PredicateNode "is-Bob")
>>    )
>> )
>>
>> So, because the implication link is scoped, the result of the variable
>> substitution is
>>
>> (AndLink
>>    (ImplicationLink
>>      (VariableNode "$foo123")
>>      (PredicateNode "is-human")
>>    )
>>    (ImplicationLink
>>      (VariableNode "$bar456")
>>      (PredicateNode "is-human")
>>    )
>>    (EvaluationLink
>>      (PredicateNode "acquainted")
>>      (ListLink
>>        (PredicateNode "is-Self")
>>        (PredicateNode "is-Bob")
>>      )
>>    )
>> )
>>
>> which is not what the unit test expects. The problem with using either
>> ScopeLink or LambdaLink is that it becomes impossible to have a stable
>> variable name -- it can be alpha-converted to anything, so any algo that
>> depends on having a fixed, well-known variable name will fail.
>>
>> In this case -- I am not sure -- if you want ImplicationLink to be
>> scoped, then the unit test is wrong.  But is the unit test is right,
>> then implication link must not be scoped.  I cannot tell which one is
>> wanted.
>>
>> --linas
>>
>>
>>
>> On Tue, Oct 11, 2016 at 12:12 PM, Nil Geisweiller
>> <ngeis...@googlemail.com <mailto:ngeis...@googlemail.com>> wrote:
>>
>>     Linas,
>>
>>     I don't have time to get into that right now. If you can point to
>>     where exactly it breaks (like a unit test on your branch) it would
>>     help. In any case I look carefully into that and reply tomorrow.
>>
>>     Nil
>>
>>
>>     On 10/11/2016 06:55 PM, Linas Vepstas wrote:
>>
>>         You made it inherit from ScopeLink, thus making the variables in
>> it
>>         implicitly scoped.  Then you added the file ImplicationLink.cc,
>>         and have
>>         notes in there, complaining about how variables are implcitly
>>         scoped.
>>         The wiki page for it, http://wiki.opencog.org/w/ImplicationLink
>>         <http://wiki.opencog.org/w/ImplicationLink> still
>>         says things that are wrong (re alpha conversion -- each lambda
>> gets
>>         alpha converted, so the "sugar syntax" section cannot possibly
>>         be right).
>>
>>         I'm asking, because I'm trying to fix #910 by doing the alpha
>>         conversion
>>         correctly, and the result of the fix is that unit tests with
>>         implication
>>         links in them now fail.  The whole thing smells bad.
>>
>>         Either ImplicationLinks do inherit from ScopeLink, in which
>>         case, there
>>         should be no complaints about how the ScopeLink works: it does
>>         the right
>>         thing.  If you don't like what the scopeLink does, then
>>         ImplicationLinks
>>         should NOT inherit from it ...
>>
>>         In either case, the wiki page needs fixing, because the alpha
>>         conversion
>>         conversation we had recently renders that page incoherent.
>>
>>         I don't really care, one way or the other, but I do need to
>>         understand
>>         the intended design well enough to be able to fix bugs, and
>>         right now, I
>>         don't understand what ImplicationLink is, or how its supposed to
>>         work.
>>
>>         --linas
>>
>>
>>
>>

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