set i = (a,k1) := k2;
A4: InsCode (halt SCMPDS) = 0 by RECDEF_2:def 1;
InsCode ((a,k1) := k2) = 7 by SCMPDS_2:19;
then (a,k1) := k2 <> halt SCMPDS by A4;
hence (a,k1) := k2 is No-StopCode by COMPOS_0:def 12; :: thesis: verum