RelationshipPatternSyntax = ('(', [SP], ')', Dash, '[', Variable, RelType, ']', Dash, '(', [SP], ')')
| ('(', [SP], ')', Dash, '[', Variable, RelType, ']', Dash, RightArrowHead, '(', [SP], ')')
| ('(', [SP], ')', LeftArrowHead, Dash, '[', Variable, RelType, ']', Dash, '(', [SP], ')')
;
Variable = SymbolicName ;
RelType = ':', [SP], RelTypeName ;
RelTypeName = SchemaName ;