The FAUST - Prover
نویسندگان
چکیده
Unfortunately first-order logic has certain limitations which are felt in many applications such as in hardware verification. The use of proof assistants like the HOL sys tem ([Gord88]) is therefore resorted to. However many theorems of higher order logic can also be proven by methods of first order logic as well. Being aware of this situation, we have implemented a prover based on Sequent Calculus within the HOL system, which can be used to mechanize proofs of necessary, but tedious l emmata required for a large proof in HOL. In order to find an efficient implementat ion, we have introduced the concept of unification in our prover. These modifications have resulted in a calculus called the "restricted sequent calculus "(T~SgQ) and an automat ic prover based on it called . ~ A L I S T 1 2 The well known sequent calculus 3 (SgQ) introduced by Gentzen [Gent35] has a major disadvantage as far as the so called "/-rules are concerned. The application of a 7-rule extends a sequent by an instance of a quantified formula of the sequent on which the rule is applied to. Unfortunately the 7-rule cannot be easily au tomated as the ' r ight ' choice of the t e rm for instantiation cannot be easily computed at the stage of rule application. The rule itself allows the use of any term, but usually only special terms lead to the desired proof. To overcome this deficiency we have introduced the concept of metavariables described in the next section.
منابع مشابه
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