Validation Rules

Structural Validation

• All referenced elements must exist
  
• All referenced picots must exist on target element
  
• No circular references in join chains
  
• Thread path must be continuous across pattern boundaries

Import Validation

• Imported files must exist and be valid TatML
  
• Import cycles not allowed
  
• Pattern names must be unique within scope

Physical Constraints

• Rings must close (implicit in syntax)
  
• Joins must be physically possible given thread path
  
• Split rings require exactly 2 shuttle specifications
  
• Cross-pattern joins must maintain thread continuity