> type, known bits, known range

>I'm not sure what you mean that they're the same thing

they're all components of the type; i have no idea what pypy does with "known bits" but deducing "range" of a value is firmly/unanimously as "type refinement" (see https://en.wikipedia.org/wiki/Refinement_type) i.e. still a part/aspect/dimension of the type not of the value.