YES

certificate:
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="cpf3HTML.xsl"?><certificationProblem xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="cpf3.xsd"><cpfVersion>3.0</cpfVersion><lookupTables><ruleTable/></lookupTables><input><infeasibilityInput><ctrs><conditionType><oriented/></conditionType><rules><rule><funapp><name>f</name><var>x</var><var>x</var></funapp><funapp><name>c</name></funapp><conditions/></rule><rule><funapp><name>a</name></funapp><funapp><name>b</name></funapp><conditions/></rule><rule><funapp><name>b</name></funapp><funapp><name>a</name></funapp><conditions/></rule></rules></ctrs><infeasibilityQuery><rule><funapp><name>f</name><funapp><name>a</name></funapp><funapp><name>c</name></funapp></funapp><funapp><name>a</name></funapp></rule></infeasibilityQuery></infeasibilityInput></input><property><infeasibility/></property><answer><yes/></answer><proof><infeasibilityProof><infeasibleCompoundConditions><name>|</name><nonreachabilityProof><nonreachableTcap/></nonreachabilityProof></infeasibleCompoundConditions></infeasibilityProof></proof><metaInformation><toolInfos><toolInfo>nonreach</toolInfo><toolInfo>version: 1.3.0.0</toolInfo></toolInfos></metaInformation></certificationProblem>