theorem :: POLYALG1:13
for L being 1-sorted
for A, B being AlgebraStr over L st A is Subalgebra of B & B is Subalgebra of A holds
AlgebraStr(# the carrier of A, the addF of A, the multF of A, the ZeroF of A, the OneF of A, the lmult of A #) = AlgebraStr(# the carrier of B, the addF of B, the multF of B, the ZeroF of B, the OneF of B, the lmult of B #)