NO
CERTIFIED

Tool output:
NO
<?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><indexToRule><index>1</index><rule><funapp><name>f</name><funapp><name>g</name><funapp><name>f</name><var>x</var></funapp></funapp></funapp><var>x</var></rule></indexToRule><indexToRule><index>2</index><rule><funapp><name>f</name><funapp><name>g</name><var>x</var></funapp></funapp><funapp><name>g</name><funapp><name>f</name><var>x</var></funapp></funapp></rule></indexToRule></ruleTable></lookupTables><input><trsWithSignature><signature><symbol><name>f</name><arity>1</arity></symbol><symbol><name>g</name><arity>1</arity></symbol></signature><trs><rules><ruleIndex>1</ruleIndex><ruleIndex>2</ruleIndex></rules></trs></trsWithSignature></input><property><confluence /></property><answer><no /></answer><proof><crDisproof><nonJoinableFork><rewriteSequence><startTerm><funapp><name>f</name><funapp><name>g</name><funapp><name>f</name><funapp><name>y1</name></funapp></funapp></funapp></funapp></startTerm><rewriteStep><positionInTerm /><ruleIndex>2</ruleIndex><funapp><name>g</name><funapp><name>f</name><funapp><name>f</name><funapp><name>y1</name></funapp></funapp></funapp></funapp></rewriteStep></rewriteSequence><rewriteSequence><startTerm><funapp><name>f</name><funapp><name>g</name><funapp><name>f</name><funapp><name>y1</name></funapp></funapp></funapp></funapp></startTerm><rewriteStep><positionInTerm /><ruleIndex>1</ruleIndex><funapp><name>y1</name></funapp></rewriteStep></rewriteSequence><capNotUnif /></nonJoinableFork></crDisproof></proof><metaInformation><toolInfos><toolInfo>Hakusan</toolInfo><toolInfo>version: 0.11</toolInfo></toolInfos></metaInformation></certificationProblem>