theorem :: BVFUNC_6:147

for Y being non empty set
for a1, a2, b1, b2, c1, c2 being Function of Y,BOOLEAN holds (((a1 'imp' a2) '&' (b1 'imp' b2)) '&' (c1 'imp' c2)) '&' ((a1 'or' b1) 'or' c1) '<' (a2 'or' b2) 'or' c2