A Machine Checked Model of Idempotent MGU Axioms For a List of Equational Constraints
نویسندگان
چکیده
Machine checked proofs of type inference algorithms often axiomatize MGU behavior as a set of axioms. Idempotent MGUs for a list of equational constraints are needed to reason about the correctness of Wand’s type inference algorithm and our extension of it. To characterize the behavior of idempotent MGUs, we propose a set of seven axioms; four of which have been proven in our earlier paper, where we formally verify that the first order unification is a model for the axioms. This paper shows that the first order unification is a model for the remaining three idempotent MGU axioms. Coq’s method of functional induction is the main proof technique used in proving the axioms.
منابع مشابه
A Machine Checked Model of Idempotent MGU Axioms For Lists of Equational Constraints
We present formalized proofs verifying that the first-order unification algorithm defined over lists of satisfiable constraints generates a most general unifier (MGU), which also happens to be idempotent. All of our proofs have been formalized in the Coq theorem prover. Our proofs show that finite maps produced by the unification algorithm provide a model of the axioms characterizing idempotent...
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