overlapConsxxsysoverlap[Ite][True][Ite]memberxysConsxxsysoverlapNilysFalsememberx'Consxxsmember[Ite][True][Ite]!EQxx'x'ConsxxsmemberxNilFalsenotEmptyConsxxsTruenotEmptyNilFalsegoalxsysoverlapxsys!EQSxSy!EQxy!EQ0SyFalse!EQSx0False!EQ00Trueoverlap[Ite][True][Ite]FalseConsxxsysoverlapxsysmember[Ite][True][Ite]Falsex'Consxxsmemberx'xsoverlap[Ite][True][Ite]TruexsysTruemember[Ite][True][Ite]TruexxsTrueTrue0Nil0member[Ite][True][Ite]3overlap2member2!EQ2S1Cons200notEmpty1overlap[Ite][True][Ite]3goal2False0INNERMOST