(petitioners, formerly married couple, claimed dependency exemption deduction and child tax credit with respect to child; pursuant to state court order, ex-wife executed form 8332 in which she agreed not to claim exemption for daughter as dependent for years at issue; ex-wife went ahead and claimed dependency exemption and child tax credit for 2007 and 2008 on belief that court order was erroneous; ex-husband also claimed child tax credit for same years and attached Form 8332 to returns; ex-wife loses because Form 8332 not rendered invalid by an error in state court order or because she signed Form 8332 due to court order to do so; thus, daughter not qualifying child under I.R.C. Sec. 152(e)).