:: deftheorem Def4 defines alpha WAYBEL29:def 4 :
for X being non empty TopSpace
for b₂ being Function of (oContMaps (X,Sierpinski_Space)),(InclPoset the topology of X) holds
( b₂ = alpha X iff for g being continuous Function of X,Sierpinski_Space holds b₂ . g = g " {1} );