ExplainingthecausesofinfeasibilityofBooleanformulashasmanypracticalapplicationsinelectronicdesignautomationandformalverificationofhardware.Furthermore,aminimumexplanationofinfeasibilitythatexcludesallirrelevantinformationisgenerallyofinterest.Asmallest-cardinalityunsatisfiablesubsetcalledaminimumunsatisfiablecorecanprovideasuccinctexplanationofinfea-sibilityandisvaluableforapplications.However,littleattentionhasbeenconcentratedonextractionofminimumunsatisfiablecore.Inthispaper,therelationshipbetweenmaximalsatisfiabilityandmini-mumunsatisfiabilityispresentedandproved,thenanefficientantcolonyalgorithmisproposedtoderiveanexactornearlyexactminimumunsatisfiablecorebasedontherelationship.Finally,ex-perimentalresultsonpracticalbenchmarkscomparedwiththebestknownapproacharereported,andtheresultsshowthattheantcolonyalgorithmstronglyoutperformsthebestpreviousalgorithm.
