theorem :: LOPBAN_8:13
for E, F, G being RealNormSpace
for f being BilinearOperator of E,F,G holds
( ( f is_continuous_on the carrier of [:E,F:] implies f is_continuous_in 0. [:E,F:] ) & ( f is_continuous_in 0. [:E,F:] implies f is_continuous_on the carrier of [:E,F:] ) & ( f is_continuous_on the carrier of [:E,F:] implies ex K being Real st
( 0 <= K & ( for x being Point of E
for y being Point of F holds ||.(f . (x,y)).|| <= (K * ||.x.||) * ||.y.|| ) ) ) & ( ex K being Real st
( 0 <= K & ( for x being Point of E
for y being Point of F holds ||.(f . (x,y)).|| <= (K * ||.x.||) * ||.y.|| ) ) implies f is_continuous_on the carrier of [:E,F:] ) )