theorem
  for l being Element of NAT, i being Element of the
  InstructionsF of STC N st InsCode i = 1 holds NIC(i, l) = {NextLoc(l,STC N)}
proof
  let l be Element of NAT, i be Element of the InstructionsF of
  STC N;
  assume
A1: InsCode i = 1;
  set M = STC N;
  consider k being Nat such that
A2: l = il.(M,k) by Th6;
  k = locnum(l,M) by A2,Def5;
  then NextLoc(l,STC N) = k+1 by Th17;
  hence thesis by A1,A2,Lm3,Th17;
end;
