[gwf]

Agreed, not with this particular design. However, you can absolutely do this just ternary numbers. You loose the ability to encode 3^n states (and are stuck w/ just 2^n), but the middle state can then be repurposed to indicate if the computation is complete (or not) as of yet.

I basically used this sort of design in a dual-rail logic framework which had 4 line-states per "data" line pair, two of which were real data bits, a third indicated unknown vs. unknown, and the fourth was unused.

See https://core.ac.uk/download/pdf/82751815.pdf, but beware that even though it doesn't look at all like ternary numbers in use, it absolute is.

[shadowofneptune]

What applications would be best suited to use this? I can't think of anything apart from scientific work that would benefit from such a specialized design.

[gwf]

None. The point of the paper was the proof technique, which was later extended to include a large family of constrained motion planning problems (i.e., problems that previously were of an unknown computational complexity could be easily mapped to the framework, thereby proving that they were PSPACE-complete).