Complex sentence: If all A's are notable, and x is an A, then x is notable is true by syllogism, but if A is notable, and x is an element of A, then x is not necessarily notable.
Split into simpler sentences: If all A's are notable, and x is an A, then x is notable is an example of a syllogism. If A is notable, and x is an element of A, then x is not necessarily notable.