Formalizing Forcing Arguments in Subsystems of Second-Order Arithmetic
نویسنده
چکیده
We show that certain model-theoretic forcing arguments involving subsystems of second-order arithmetic can be formalized in the base theory, thereby converting them to effective proof-theoretic arguments. We use this method to sharpen conservation theorems of Harrington and Brown-Simpson, giving an effective proof that WKL+0 is conservative over RCA0 with no significant increase in the lengths of proofs.
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عنوان ژورنال:
- Ann. Pure Appl. Logic
دوره 82 شماره
صفحات -
تاریخ انتشار 1996