let F be ext-real-membered set ; :: thesis: for f being ExtReal
for e being set st e in F -- f holds
ex w being Element of ExtREAL st
( e = w - f & w in F )
let f be ExtReal; :: thesis: for e being set st e in F -- f holds
ex w being Element of ExtREAL st
( e = w - f & w in F )
let e be set ; :: thesis: ( e in F -- f implies ex w being Element of ExtREAL st
( e = w - f & w in F ) )
F -- f = { (w - f) where w is Element of ExtREAL : w in F } by Th169;
hence ( e in F -- f implies ex w being Element of ExtREAL st
( e = w - f & w in F ) ) ; :: thesis: verum