,-------------------------.                              ,---------------------------.                                                
  |Functional Specifications|                              |Supplemental Specifications|                                                
  |-------------------------|                              |---------------------------|                                                
  `-------------------------'                              `---------------------------'                                                
                |                                                                                                                       
                |                                                                                                                       
,------------------------------.  ,----------.   ,------------------.   ,------------------------------.   ,---------------------------.
|Domain Functional Requirements|  |Principles|   |System Constraints|   |System Functional Requirements|   |Non-Functional Requirements|
|------------------------------|  |----------|   |------------------|   |------------------------------|   |---------------------------|
`------------------------------'  `----------'   `------------------'   `------------------------------'   `---------------------------'