List operations not working when duplicate identities in the list descriptors

[MichelSc]

Consider the graph

@prefix list: <http://www.w3.org/2000/10/swap/list#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix : <urn:example:> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .

:la1 
    rdf:first :a1;
    rdf:rest :la2, rdf:nil.
#    rdf:rest rdf:nil.

:la2 owl:sameAs rdf:nil.

:let :mylist :la1.

{
    :let :mylist ?list.
    ?list list:length ?length.
}=>{
    :result :length ?length.
}.

Running eye 11.10.26 will produce the error

** ERROR ** eam ** malformed_list_extra_rest(<urn:example:la1>,<urn:example:la2>,[])

This is unexpected. List :la1 is the simple list ( :a1) and I expect to get its length 1.

Other operations will lead to the same error.

Note that the consequence of owl:sameAs have been manually added so we do not need to include extra rules.

[josd]

This error is thrown on the syntax level but the following is fine

@prefix list: <http://www.w3.org/2000/10/swap/list#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix : <urn:example:> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .

:la1 
    rdf:first :a1;
    rdf:rest rdf:nil, rdf:nil.

:let :mylist :la1.

{
    :let :mylist ?list.
    ?list list:length ?length.
}=>{
    :result :length ?length.
}.

and gives

@prefix : <urn:example:>.

:let :mylist :la1.
:result :length 1 .

[MichelSc]

Unfortunately, this does not solve the issue (nor my case).

Support for equivalence classes is in our eyes very valuable (if not essential).

Hard coded support avoiding combinatorics explosion even better (like https://graphdb.ontotext.com/documentation/11.0/sameas-optimisation.html).