graph terms vs nested triples

To poke a bit it the perceived impossibility of graph terms: 
what is the difference between a nested triple term, e.g.

    << << :a :b :c >> :d :e >>

and a graph term? How is it categorically different from e.g.

    << :a :b :c . 
       :x :d :e >>

? 

Or at least different enough that the former was for a decade by and large considered unproblematic (modulo concerns w.r.t. computational complexity) whereas the latter raises all kinds of vague concerns?


Best,
Thomas

Received on Thursday, 21 December 2023 18:04:45 UTC