::= '<' (|'#'|'_'|'/'|'&') ([^> ])* '>' ::= ? ':' ::= ? ':' (|)? ::= '_:' (|) ::= '_:' (|) ::= ('?'|'$') (|) ::= + ('-' ()+)? <#A2Z> ::= [a-zAZ] <#A2ZN> ::= [a-zA-Z0-9] ::= ::= [0-9]+ '.' [0-9]* ? | '.' ([0-9])+ ? | ([0-9])+ <#EXPONENT> ::= [eE] [+-]? [0-9]+ ::= "'" ( ([^'\\\n\r]) | ('\\' [^\n\r]) )* "'" ::= '"' ( ([^"\\\n\r]) | ('\\' [^\n\r]) )* '"' ::= [0-9]+ [] ::= 'base' [] ::= 'prefix' [] ::= 'select' [] ::= 'describe' [] ::= 'construct' [] ::= 'ask' [] ::= 'distinct' [] ::= 'limit' [] ::= 'where' [] ::= 'filter' [] ::= 'regexp' [] ::= 'graph' [] ::= 'union' [] ::= 'optional' [] ::= 'bound' [] ::= 'str' [] ::= 'datatype' [] ::= 'lang' [] ::= 'isURI' [] ::= 'isBlank' [] ::= 'isLiteral' [] ::= 'regexp' [] ::= 'true' [] ::= 'false' [] ::= 'a' [] ::= '(' [] ::= ')' [] ::= '{' [] ::= '}' [] ::= '[' [] ::= ']' [] ::= ';' [] ::= ',' [] ::= '.' [] ::= '>' [] ::= '<' [] ::= '!' [] ::= '~' [] ::= '?' [] ::= ':' [] ::= '=' [] ::= '!=' [] ::= '<=' [] ::= '>=' [] ::= '||' [] ::= '&&' [] ::= '++' [] ::= '--' [] ::= '+' [] ::= '-' [] ::= '*' [] ::= '/' [] ::= '!~' [] ::= '^^' [] ::= '@' <#NCCHAR1> ::= [A-Z] | [a-z] | [#x00C0-#x00D6] | [#x00D8-#x00F6] | [#x00F8-#x02FF] | [#x0370-#x037D] | [#x037F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFFFF] <#NCCHAR_END> ::= | '_' | '-' | [0-9] | #x00B7 <#NCCHAR_FULL> ::= | '.' <#NCNAME1> ::= (* )? <#NCNAME2> ::= '_' (* )? <#NCNAME_PREFIX> ::= *