:: deftheorem Def1 defines RealFuncAdd FUNCSDOM:def 1 :
for A being set
for b₂ being BinOp of (Funcs (A,REAL)) holds
( b₂ = RealFuncAdd A iff for f, g being Element of Funcs (A,REAL) holds b₂ . (f,g) = addreal .: (f,g) );