YES activeU11ttNmarkNactiveU21ttMNmarksplusNMactiveU31ttmark0activeU41ttMNmarkplusxNMNactiveandttXmarkXactiveisNat0markttactiveisNatplusV1V2markandisNatV1isNatV2activeisNatsV1markisNatV1activeisNatxV1V2markandisNatV1isNatV2activeplusN0markU11isNatNNactiveplusNsMmarkU21andisNatMisNatNMNactivexN0markU31isNatNactivexNsMmarkU41andisNatMisNatNMNactiveU11X1X2U11activeX1X2activeU21X1X2X3U21activeX1X2X3activesXsactiveXactiveplusX1X2plusactiveX1X2activeplusX1X2plusX1activeX2activeU31XU31activeXactiveU41X1X2X3U41activeX1X2X3activexX1X2xactiveX1X2activexX1X2xX1activeX2activeandX1X2andactiveX1X2U11markX1X2markU11X1X2U21markX1X2X3markU21X1X2X3smarkXmarksXplusmarkX1X2markplusX1X2plusX1markX2markplusX1X2U31markXmarkU31XU41markX1X2X3markU41X1X2X3xmarkX1X2markxX1X2xX1markX2markxX1X2andmarkX1X2markandX1X2properU11X1X2U11properX1properX2properttokttproperU21X1X2X3U21properX1properX2properX3propersXsproperXproperplusX1X2plusproperX1properX2properU31XU31properXproper0ok0properU41X1X2X3U41properX1properX2properX3properxX1X2xproperX1properX2properandX1X2andproperX1properX2properisNatXisNatproperXU11okX1okX2okU11X1X2U21okX1okX2okX3okU21X1X2X3sokXoksXplusokX1okX2okplusX1X2U31okXokU31XU41okX1okX2okX3okU41X1X2X3xokX1okX2okxX1X2andokX1okX2okandX1X2isNatokXokisNatXtopmarkXtopproperXtopokXtopactiveX2.1U1122tt01U2134s11plus24U3115002U4136x26and23top10active11U11212tt0mark11U213321s11plus212U311100U413321x212and212isNat11proper11ok11top11activeU11X1X2U11activeX1X2activeU21X1X2X3U21activeX1X2X3activesXsactiveXactiveplusX1X2plusactiveX1X2activeplusX1X2plusX1activeX2activeU31XU31activeXactiveU41X1X2X3U41activeX1X2X3activexX1X2xactiveX1X2activexX1X2xX1activeX2activeandX1X2andactiveX1X2U11markX1X2markU11X1X2U21markX1X2X3markU21X1X2X3smarkXmarksXplusmarkX1X2markplusX1X2plusX1markX2markplusX1X2U31markXmarkU31XU41markX1X2X3markU41X1X2X3xmarkX1X2markxX1X2xX1markX2markxX1X2andmarkX1X2markandX1X2properU11X1X2U11properX1properX2properttokttproperU21X1X2X3U21properX1properX2properX3propersXsproperXproperplusX1X2plusproperX1properX2properU31XU31properXproper0ok0properU41X1X2X3U41properX1properX2properX3properxX1X2xproperX1properX2properandX1X2andproperX1properX2properisNatXisNatproperXU11okX1okX2okU11X1X2U21okX1okX2okX3okU21X1X2X3sokXoksXplusokX1okX2okplusX1X2U31okXokU31XU41okX1okX2okX3okU41X1X2X3xokX1okX2okxX1X2andokX1okX2okandX1X2isNatokXokisNatXtopmarkXtopproperXtopokXtopactiveX1active121U1122112U213212213s121plus22122U31121U413212223x22122and22122mark1211proper111tt00ok121000isNat121top111activeU11X1X2U11activeX1X2activeU21X1X2X3U21activeX1X2X3activesXsactiveXactiveplusX1X2plusactiveX1X2activeplusX1X2plusX1activeX2activeU31XU31activeXactiveU41X1X2X3U41activeX1X2X3activexX1X2xactiveX1X2activexX1X2xX1activeX2activeandX1X2andactiveX1X2properU11X1X2U11properX1properX2properttokttproperU21X1X2X3U21properX1properX2properX3propersXsproperXproperplusX1X2plusproperX1properX2properU31XU31properXproper0ok0properU41X1X2X3U41properX1properX2properX3properxX1X2xproperX1properX2properandX1X2andproperX1properX2properisNatXisNatproperXU11okX1okX2okU11X1X2U21okX1okX2okX3okU21X1X2X3sokXoksXplusokX1okX2okplusX1X2U31okXokU31XU41okX1okX2okX3okU41X1X2X3xokX1okX2okxX1X2andokX1okX2okandX1X2isNatokXokisNatXtopokXtopactiveX1active121U11222112U2132111213s111plus211112U31111U4132111213x211112and211112proper1121tt00ok1121000isNat111top111activesXsactiveXactiveU31XU31activeXproperU11X1X2U11properX1properX2properttokttproperU21X1X2X3U21properX1properX2properX3propersXsproperXproperplusX1X2plusproperX1properX2properU31XU31properXproper0ok0properU41X1X2X3U41properX1properX2properX3properxX1X2xproperX1properX2properandX1X2andproperX1properX2properisNatXisNatproperXU11okX1okX2okU11X1X2U21okX1okX2okX3okU21X1X2X3sokXoksXplusokX1okX2okplusX1X2U31okXokU31XU41okX1okX2okX3okU41X1X2X3xokX1okX2okxX1X2andokX1okX2okandX1X2isNatokXokisNatX1active121s1221U31121proper121U1122122tt01ok1111U2132212223plus212122001U413111213x22122and22122isNat1221activeU31XU31activeXproperU11X1X2U11properX1properX2properttokttproperU31XU31properXproper0ok0properU41X1X2X3U41properX1properX2properX3properxX1X2xproperX1properX2properandX1X2andproperX1properX21active121U311121proper121U11211112tt01ok111001U4131211213x21112and212122properxX1X2xproperX1properX21proper110x200AProVEAProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Statistics for single proof: 100.00 % (7 real / 0 unknown / 0 assumptions / 7 total proof steps)http://aprove.informatik.rwth-aachen.deJohnDoe