> Using the XSyntax language modeled after BNF. The XSyntax language uses a syntax of ConciseXML. A XSyntax expression has a name and a pattern which describes the syntax. examples= true" "null"/> invalid="/> /> examples= invalid= /> /> /> examples= invalid= /> /> /> examples= invalid= /> /> examples= invalid= /> /> a_char /> examples= invalid= /> cxs.symbol /> char.semicolon /> examples= invalid= /> /> /> cxs.expression /> examples= invalid= /> examples=" "" "bar"/> invalid="/> /> "<" cxs.expression cxs.arguments "/>" examples=" ""/> invalid="/> /> "<" cxs.expression cxs.optional_arguments cxs.optional_whitespace ">" cxs.expressions "" examples=" "bar"/> invalid="/> /> /> /> examples= invalid= invalid= examples= =6" "'foo'= 6"/> invalid= />