Hi espadrine. I appreciate your well-intentioned comment, but I believe the issue here is not about grasping the symmetry argument, rather it's that the symmetry argument is not an answer to the the actual question I've been posing since the beginning.
Please correct me if I'm wrong—but the symmetry argument is basically: Nock could be classified as a concatenative combinatory logic, which is a variation of "classical" combinatory logic; this classical variation, or a particular incarnation like the SKI combinator calculus, can be viewed as a variation on the untyped lambda calculus.
That establishes an association between Nock, the alternative posted by xkapastel (which is a concatenative combinatory logic), and the lambda calculus.
So from here we can say, "why not just use the non-obscure bit of combinatory logic instead?" (we choose this over lambda calculus since Nock's approach appears concentative too, avoiding lambdas)
And my answer is that if all you need is a concatenative universal model of computation—then you're done!
But—where is it actually established that that is the only requirement for Nock in the context of Urbit? That is the question I've been asking the whole time, and which is not answered by the symmetry argument.
Nock's essential structure may be that of a concatenative combinatory logic, but that doesn't mean there aren't other aspects of its design which are important for how it relates to other particulars of the Urbit system (for instance: maybe this variation has nice performance properties in connection with other parts of Urbit—I don't know).
Please correct me if I'm wrong—but the symmetry argument is basically: Nock could be classified as a concatenative combinatory logic, which is a variation of "classical" combinatory logic; this classical variation, or a particular incarnation like the SKI combinator calculus, can be viewed as a variation on the untyped lambda calculus.
That establishes an association between Nock, the alternative posted by xkapastel (which is a concatenative combinatory logic), and the lambda calculus.
So from here we can say, "why not just use the non-obscure bit of combinatory logic instead?" (we choose this over lambda calculus since Nock's approach appears concentative too, avoiding lambdas)
And my answer is that if all you need is a concatenative universal model of computation—then you're done!
But—where is it actually established that that is the only requirement for Nock in the context of Urbit? That is the question I've been asking the whole time, and which is not answered by the symmetry argument.
Nock's essential structure may be that of a concatenative combinatory logic, but that doesn't mean there aren't other aspects of its design which are important for how it relates to other particulars of the Urbit system (for instance: maybe this variation has nice performance properties in connection with other parts of Urbit—I don't know).