This note makes one engineering claim explicit: logic, state, reconfiguration, and growth can all be expressed inside one Boolean transition system built from 2:1 multiplexers, wires, constants, feedback, and local configuration registers. The separate machine layers people usually talk about are presentations on top of the same substrate.
Build a computational substrate from only wires, constants, and 2:1 multiplexers, then allow feedback and replication. Digital computation is routinely explained through many formalisms (machines, grammars, lambda terms), while hardware practice already runs on a simpler invariant: a clocked next-state function over bits. A single omission keeps the public model fractured: sequential switching networks—and the fact that reconfiguration is itself a Boolean, clocked process. This paper defines an explicit model in which (i) every primitive is Boolean (multiplexers, wires, constants), (ii) time is only state-to-state transition over registers realizable by those same primitives, (iii) programming is the installation of constraints into configuration registers, and (iv) unbounded memory is obtained by unbounded tiling (including physical self-assembly as one admissible growth mechanism). Under these assumptions the model is equivalent in power to standard universal models while remaining a single, uniform Boolean transition system.
The primary live Cartilage demo instantiates series of 6x6 MUX tile blocks in a nested manner from the left edge reconfiguration port area, streaming mere SPI bits of those areas.
You also can inspect the code of a ShaderCode implementation of Cartilage originally published in Summer 2021 as a priority date claim so we don't have to mess with patents.