claim: Joni Mitchell quit smoking.
evidence: William Edge may refer to  :. William Edge -LRB- mathematician -RRB- -LRB- 1904 -- 1997 -RRB- , British mathematician most known for his work in finite geometry. Sir William Edge , 1st Baronet -LRB- 1880 -- 1948 -RRB- , British Liberal , later National Liberal politician and businessman