theorem Th15: :: FUNCSDOM:15

for A being set
for f, g, h being Element of Funcs (A,REAL) holds (RealFuncMult A) . (f,((RealFuncAdd A) . (g,h))) = (RealFuncAdd A) . (((RealFuncMult A) . (f,g)),((RealFuncMult A) . (f,h)))