[rb-general] rb formalism

[Daniel Shahaf]

Eric Myhre wrote on Tue, 18 Dec 2018 11:48 +0100:
> h(➡) → h(■) vs
> h(➡) → h(➡■) --

What is the argument to the last of these h()'s?

I get that h() is a cryptographic hash function, that ➡ is a callable
function and actual parameters for it (which can be evaluated to produce
some sort of output), and that ■ is an actual parameter.  All that makes
perfect sense.  The part I don't understand is what the juxtaposition
"➡■" means.  Does it mean to hash the 2-tuple (➡,■)?

Thanks,

Daniel