YES

certificate:
<?xml version='1.0' ?><certificationProblem xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="cpf3.xsd"><cpfVersion>3.0</cpfVersion><lookupTables /><input><infeasibilityInput><ctrs><conditionType><oriented /></conditionType><rules><rule><funapp><name>b</name></funapp><funapp><name>a</name></funapp><conditions /></rule><rule><funapp><name>a</name></funapp><funapp><name>b</name></funapp><conditions /></rule><rule><funapp><name>f</name><var>x</var><var>x</var></funapp><funapp><name>c</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><infeasibleEquation><rule><funapp><name>f</name><funapp><name>a</name></funapp><funapp><name>c</name></funapp></funapp><funapp><name>a</name></funapp></rule><nonreachabilityProof><nonreachableCorewritePair><interpretation><type><polynomial><domain><negativeIntegers /></domain><degree>1</degree></polynomial></type><interpret><name>b</name><arity>0</arity><integer>0</integer></interpret><interpret><name>a</name><arity>0</arity><integer>0</integer></interpret><interpret><name>f</name><arity>2</arity><sum><integer>-1</integer><product><integer>0</integer><variable>1</variable></product><product><integer>0</integer><variable>2</variable></product></sum></interpret><interpret><name>c</name><arity>0</arity><integer>-1</integer></interpret></interpretation></nonreachableCorewritePair></nonreachabilityProof></infeasibleEquation></infeasibilityProof></proof></certificationProblem>