Different mechanical verifiers vary considerably in their capabilities. A relatively simple verifier might require that assertions giving all relevant information are attached between every pair of successive statements (simple or compound), and would present any nontrivial verification conditions to the user for manual proof; this approach is sometimes called an assertion checker. A more sophisticated mechanical verifier requires only major assertions to be attached prior to verification (perhaps only the input assertion and output assertion) and is able to generate its own intermediate assertions as necessary. Further, the theorem prover is capable of proving complex verification conditions, perhaps presenting only the occasional lemma to the user for confirmation.
"mechanical verifier." A Dictionary of Computing. . Encyclopedia.com. (August 17, 2018). http://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/mechanical-verifier
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