$Revision$
$Date$
substeps — A wrapper for steps that occur within steps in a procedure
substeps ::=
(step+)| 
                         Name  | 
                     
                         Type  | 
                     
                         Default  | 
                  |||
| performance | 
                        
  | 
                     "required" | 
               A Procedure describes a sequence of
               Steps that a reader is expected to perform.  If a
               finer level of granularity is required for some steps, you can
               use SubSteps to embed substeps within a
               Step.
               
            
               SubSteps contain Steps, so substeps can
               be nested to any depth.
               
            
                        Performance specifies whether 
                        particular set of Substep in a Procedure must 
                        be performed or is optional.