Premise: The Lei Áurea (] ; English: Golden Law ), adopted on May 13, 1888, was the law that abolished slavery in Brazil. It was signed by Isabel, Princess Imperial of Brazil (1846–1921), an opponent of slavery, who acted as regent to Emperor Dom Pedro II, who was in Europe.
Hypothesis: The Lei Aurea law which was adopted on May 13, 1888 abolished slavery.  It was opposed by Princess Imperial.