theorem Th14: :: PRALG_3:14

for I being non empty set
for S being non empty non void ManySortedSign
for A being MSAlgebra-Family of I,S
for o being OperSymbol of S
for x being Element of Args (o,(product A)) holds x in Funcs ((dom (the_arity_of o)),(Funcs (I,(union { ( the Sorts of (A . i9) . s9) where i9 is Element of I, s9 is Element of the carrier of S : verum } ))))