1176   \end{center}

  1176   \end{center}

  1177 

  1177 

  1178   \noindent

  1178   \noindent

  1179   Running such a program means we start with the first instruction

  1179   Running such a program means we start with the first instruction

  1180   then execute one instructions after the other, unless there is a jump.  For

  1180   then execute one instructions after the other, unless there is a jump.  For

  1182   we jump back to the first instruction thereby closing the loop.  Like with our

  1182   we jump back to the first instruction thereby closing the loop.  Like with our

  1183   Turing machines, we fetch instructions from an abacus program such

  1183   Turing machines, we fetch instructions from an abacus program such

  1184   that a jump out of ``range'' behaves like a @{term "Nop"}-action. In

  1184   that a jump out of ``range'' behaves like a @{term "Nop"}-action. In

  1185   this way it is again easy to define a function @{term steps} that

  1185   this way it is again easy to define a function @{term steps} that

  1186   executes @{term n} instructions of an abacus program. A \emph{configuration}

  1186   executes @{term n} instructions of an abacus program. A \emph{configuration}