Mux optimizations
some experiments
use repIf for triples and quadruples
transparent graph background
"swapD" & "swapR" --> "swapDom" & "swapRan"
swap names of accumL/accumR, shiftL/shiftR, shiftLF/shiftRF (e.g., "from right" rather than "rightward")
drop ConstCat
it
shiftL/shiftR name swap