Background - Irreversible Fitness Distributions

• Number of program increases exponentially with their size.
  Most programs are big.

  A number of results apply in the limit as programs get bigger. I.e. they apply to most programs.

  In practise convergence to limit can be rapid, so reasonably sized programs behave much like very big ones.

  
  

• Convergence can be proved for simple systems. Program consists of a simple linear sequence of instructions. No loops. No jumps. Inputs not write protected.

  
  

• Most such irreversible programs loose information. Their inputs cannot be inferred from their outputs.

  Output does not depend on input. I.e. output is a constant.

  In the limit, the fraction of interesting linear programs becomes zero.