Premise: Then, ruthless urban planner Baron Haussmann swept away almost all the medieval and 17th-century structures, leaving just place Dauphine and rue Chanoinesse (ancient home of the cathedral canons) as signs of the island's once rich residential life.

Hypothesis: Baron Haussmann was a ruthless urban planner who removed almost all of the medieval and 17th-century structures.
Relation: entailment