theorem :: FINSEQ_2:75
for D, D9, E being non empty set
for d1, d2 being Element of D
for d19, d29 being Element of D9
for F being Function of [:D,D9:],E
for p being FinSequence of D
for q being FinSequence of D9 st p = <*d1,d2*> & q = <*d19,d29*> holds
F .: (p,q) = <*(F . (d1,d19)),(F . (d2,d29))*>