If `s` is a nonzerodivisor modulo `I`, then `ℓ(R/(I + (t s))) = ℓ(R/(I + (t))) + ℓ(R/(I + (s)))`.

Initializing...

If `s` is a nonzerodivisor modulo `I`, then `ℓ(R/(I + (t s))) = ℓ(R/(I + (t))) + ℓ(R/(I + (s)))`. · Prove2Me