I'm asking about "W" and not "X" here.
Claim 1: A system comprising X, Y, Z.
Claim 2: The system of claim 1, wherein the X is connected to a W.
Claim 3: The system of claim 1, wherein the W is P connected to U.
In claim 3, I introduced "w" with the definite article. Even though the parent claim (claim 1) does not mention "w", a sister claim (claim 2) already mentioned "w" so antecedent basis is already established. Is it correct?