__O++++++++++++++++P__+
__+++++++++_O+++P++++P
__+old file library+__
__+++++++++__+old+ new+
__L+++++++++++++++++_ 
__         _L+++++++++
__+       +        +_ 
__                 _+_+
__+reverse+ advance+_ 
__                 _+_+
__L+++++++++++++++++_ 
__                 _+
__+                +_ 
__ _O++++++++++++++++P
__+                +_ 
__ _+ new file name? +
__+                +_ 
__ _L+++++++++++++++++
__+                +_ 
__ _+                +
__+                +_ 
__ _+                +
__+                +_ 
__ _L+++++++++++++++++
__+                +_ 
__ _+__              _+_+
__L+++++++++++++++++_ 
__ _+_+              _+_+
__+       +        +_+
__+_+_+              _+_+
__+copy   + modify +__+
__++_+              _+_+
__L+++++++++++++++++_ 
__                 _+_+
__+       +        +_ 
__                 _+_+
__+crunch + replace+_ 
__                 _+_+
__L+++++++++++++++++_ 
__                 _+
__+       +        +_ 
__   _O++++++P+++++++P
__+scratch+ view   +_+
__++____+cancel+ accept+
__L+++++++++++++++++__+
__++_+_L+++++++++++++++