Status: IN
The lookup abstraction trio (Counter, set, binary search) is the load-bearing joint between the pipeline's preprocessing and scanning phases — each preprocessing paradigm (hash or sort) establishes exactly the data structure one of these abstractions queries, making the lookup the mechanism that converts preprocessing investment into linear-time scan payoff across both pipeline instantiations.
Connects the abstract pipeline decomposition (two forms) with the concrete computational mechanism (three lookup abstractions) that makes each form work
Depends on (SL): lookup-abstractions-enable-linear-time-across-paradigms, canonical-pipeline-has-exactly-two-instantiations