for U0, U1 being Universal_Algebra
for o0 being operation of U0
for o1 being operation of U1
for n being Nat st U0 is SubAlgebra of U1 & n in dom the charact of U0 & o0 = the charact of U0 . n & o1 = the charact of U1 . n holds
arity o0 = arity o1