Modules1

Nesting switch functions is like algebra.

 

In this example, a humbucker splitter is nested inside a phase swapper. Accordingly, the orange circuitry is enveloped by the blue circuitry.

 

Splitter and PhaseSwapper: We can consider each of those functions as a separate "subsystem".

 

The coil splitter is in orange. The control is a 1P2T switch. One way to consider this subsystem is: "Switch position#1 shorts the South coil and pos#2 shorts the North coil; we don't (yet) know/care which end gets assigned (later) the Hot and which get the Ground."

 

The phase swapper is in blue. The control is a 2P2T that dictates "#Down assigns the Hot to the Left side of the orange susbsystem and Ground to the right, and #Up assigns Hot-right, Ground-Left; we don't know/care what's inside the orange subsystem."

 

There are four drawings here: Nested-Overview, #A=Splitter, #B=PhaseSwap and #C=Nested-Expanded

 

Critical to this way of thinking, #B shows the detail of the PhaseSwapper mixed with an overview of the Splitter. Verbally: "PhaseSwap whatever is in the orange subsystem." Analogous to Blue = PhaseSwap(Orange)" in algebra. The word "whatever" shows that we don't need to consider what's inside the orange circuitry at this point of the design process.

 

Working backwards from there, we could say the first drawing amounts to "Overview = Blue(Orange)."

 

Then the final drawing may be obtained by defining the details of each of those separate subsystems (#A and #B) and then putting them together with their details expressed (#C).

Done