reserve n,i,j,k for Nat;
reserve T for TuringStr,
  s for All-State of T;

theorem Th18:
  for T being TuringStr,t be Tape of T,s,n1,n2 be Element of NAT
st t storeData <*s,n1,n2*> holds t is_1_between s,s+n1+2 & t is_1_between s+n1+
  2,s+n1+n2+4
proof
  let T be TuringStr,t be Tape of T,s,n1,n2 be Element of NAT;
  set f=<*s,n1,n2*>;
  assume
A1: t storeData f;
A2: len f=3 by FINSEQ_1:45;
  Sum Prefix(f,1)+2*(1-1)=s & Sum Prefix(f,1+1)+2*1=s+n1+2 by Th5;
  hence t is_1_between s,s+n1+2 by A1,A2;
  Sum Prefix(f,2)+2*(2-1)=s+n1+2 & Sum Prefix(f,2+1)+2*2=s+n1+n2+4 by Th5;
  hence thesis by A1,A2;
end;
