Premise: The present state of the cathedral owes much to Eugane Viollet-le-Duc, who from 1845 to 1863 painstakingly restored it following the ravages of the 18th century, caused more by pre-Revolutionary meddlers than by revolutionaries who stripped it of religious symbols.

Hypothesis: Eugane Viollet-le-Duc spent 18 years to restore the cathedral.
Relation: entailment