let H be CTL-formula; :: thesis: ( H is ExistNext implies H . 1 = 2 )
assume H is ExistNext ; :: thesis: H . 1 = 2
then consider H1 being CTL-formula such that
A1: H = EX H1 by Def17;
thus H . 1 = 2 by A1, FINSEQ_1:58; :: thesis: verum