The unstated observation made in Unwanted Expansion is that if every variable is equal to 2, then every operation in the expression must increase the total by a

The unstated observation made in Unwanted Expansion is that if every variable is equal to 2, then every operation in the expression must increase the total by at least 2 (note that only addition and multiplication are allowed, not subtraction or division). In other words, an expression with n terms or factors will always evaluate to at least 2n. This puts an upper bound on how far any finite-valued expression can be expanded.