Author here. The theme is "You could have invented BDDs" -- the article works up to them in hopefully-natural steps, with some applications along the way. The Python code is shorter than I've been able to find elsewhere.
Fabian Giesen pointed out last night that the example "carry-lookahead adder" was misnamed and it's a kind of https://en.wikipedia.org/wiki/Carry-select_adder. Oops. Going to fix that soon. I'd read the carry-lookahead article and was like "this derivation seems right but I don't see how you might invent it." Trying to fix that ended up reinventing something different. I should've noted there in the article that I felt iffy about what I'd called the circuit, even though it was functionally equivalent. (Better still of course to code up Wikipedia's version and check structural equivalence, if there'd been time.)
Fabian Giesen pointed out last night that the example "carry-lookahead adder" was misnamed and it's a kind of https://en.wikipedia.org/wiki/Carry-select_adder. Oops. Going to fix that soon. I'd read the carry-lookahead article and was like "this derivation seems right but I don't see how you might invent it." Trying to fix that ended up reinventing something different. I should've noted there in the article that I felt iffy about what I'd called the circuit, even though it was functionally equivalent. (Better still of course to code up Wikipedia's version and check structural equivalence, if there'd been time.)