> if any claim gets invalidated, the rest that rely on it are useless. This misunderstanding came up in another thread. If a dependent claim is invalidated, th

> if any claim gets invalidated, the rest that rely on it are useless. This misunderstanding came up in another thread. If a dependent claim is invalidated, then it invalidates the claims it depends from, but not the other way around. For example, consider the following claims: 1. A method comprising steps A, B, and C. 2. The method of claim 1, further comprising step D. If the prior art only teaches claim 1, then claim 2 could still be valid if the addition of step D is non-obvious over the prior art. If the prior art teaches claim 2, however, then claim 1 is also invalid.