[pnw_hazor]

Claim language such as "determining foo based on x, y, and y" is leaving the door open for a judge to interpret the limitation as requiring "x, y, AND z"

Better language (assuming it is how the thing works) is: "determining foo based on one or more of x, y, or z"

The strange language in claims (and patents in general) is a response to litigation. Good patent prosecutors (the patent attorneys that draft patents) watch court cases and adjust their claim language accordingly.

Good patent litigators try to tear up or dissect the claim language (as well as everything else...). So patent prosecutors should draft with an eye toward litigation and include language that inoculates a patent from common or obvious attacks.