theorem Th60: :: MEASUR11:64

for X being non empty set
for f, g being PartFunc of X,ExtREAL holds
( - (f + g) = (- f) + (- g) & - (f - g) = (- f) + g & - (f - g) = g - f & - ((- f) + g) = f - g & - ((- f) + g) = f + (- g) )