cache = outerCache[ type ] || [];
nodeIndex = cache[0] === dirruns && cache[1];
diff = cache[0] === dirruns && cache[2];
node = nodeIndex && parent.childNodes[ nodeIndex ];

while ( (node = ++nodeIndex && node && node[ dir ] ||

// Fallback to seeking `elem` from the start
(diff = nodeIndex = 0) || start.pop()) ) {

// When found, cache indexes on `parent` and break
if ( node.nodeType === 1 && ++diff && node === elem ) {
outerCache[ type ] = [ dirruns, nodeIndex, diff ];
break;
}
}

// Use previously-cached element index if available
} else if ( useCache && (cache = (elem[ expando ] || (elem[ expando ] = {}))[ type ]) && cache[0] === dirruns ) {
diff = cache[1];

// xml :nth-child(...) or :nth-last-child(...) or :nth(-last)?-of-type(...)
} else {
// Use the same loop as above to seek `elem` from the start
while ( (node = ++nodeIndex && node && node[ dir ] ||
(diff = nodeIndex = 0) || start.pop()) ) {

if ( ( ofType ? node.nodeName.toLowerCase() === name : node.nodeType === 1 ) && ++diff ) {
// Cache the index of each encountered element
if ( useCache ) {
(node[ expando ] || (node[ expando ] = {}))[ type ] = [ dirruns, diff ];
}

if ( node === elem ) {
break;
}
}
}
}

// Incorporate the offset, then check against cycle size
diff -= last;
return diff === first || ( diff % first === 0 && diff / first >= 0 );
}
};
},

"PSEUDO": function( pseudo, argument ) {
// pseudo-class names are case-insensitive
// http://www.w3.org/TR/selectors/#pseudo-classes
// Prioritize by case sensitivity in case custom pseudos are added with uppercase letters
// Remember that setFilters inherits from pseudos
var args,
fn = Expr.pseudos[ pseudo ] || Expr.setFilters[ pseudo.toLowerCase() ] ||
Sizzle.error( "unsupported pseudo: " + pseudo );

// The user may use createPseudo to indicate that
// arguments are needed to create the filter function
// just as Sizzle does
if ( fn[ expando ] ) {
return fn( argument );
}

// But maintain support for old signatures
if ( fn.length > 1 ) {
args = [ pseudo, pseudo, "", argument ];
return Expr.setFilters.hasOwnProperty( pseudo.toLowerCase() ) ?
markFunction(function( seed, matches ) {
var idx,
matched = fn( seed, argument ),
i = matched.length;
while ( i-- ) {
idx = indexOf( seed, matched[i] );
seed[ idx ] = !( matches[ idx ] = matched[i] );
}
}) :
function( elem ) {
return fn( elem, 0, args );
};
}

return fn;
}
},

pseudos: {
// Potentially complex pseudos
"not": markFunction(function( selector ) {
// Trim the selector passed to compile
// to avoid treating leading and trailing
// spaces as combinators
var input = [],
results = [],
matcher = compile( selector.replace( rtrim, "$1" ) );

return matcher[ expando ] ?
markFunction(function( seed, matches, context, xml ) {
var elem,
unmatched = matcher( seed, null, xml, [] ),
i = seed.length;

// Match elements unmatched by `matcher`
while ( i-- ) {
if ( (elem = unmatched[i]) ) {
seed[i] = !(matches[i] = elem);
}
}
}) :
function( elem, context, xml ) {
input[0] = elem;
matcher( input, null, xml, results );
// Don't keep the element (issue #299)
input[0] = null;
return !results.pop();
};
}),

"has": markFunction(function( selector ) {
return function( elem ) {
return Sizzle( selector, elem ).length > 0;
};
}),

"contains": markFunction(function( text ) {
text = text.replace( runescape, funescape );
return function( elem ) {
return ( elem.textContent || elem.innerText || getText( elem ) ).indexOf( text ) > -1;
};
}),

// "Whether an element is represented by a :lang() selector
// is based solely on the element's language value
// being equal to the identifier C,
// or beginning with the identifier C immediately followed by "-".
// The matching of C against the element's language value is performed case-insensitively.
// The identifier C does not have to be a valid language name."
// http://www.w3.org/TR/selectors/#lang-pseudo
"lang": markFunction( function( lang ) {
// lang value must be a valid identifier
if ( !ridentifier.test(lang || "") ) {
Sizzle.error( "unsupported lang: " + lang );
}
lang = lang.replace( runescape, funescape ).toLowerCase();
return function( elem ) {
var elemLang;
do {
if ( (elemLang = documentIsHTML ?
elem.lang :
elem.getAttribute("xml:lang") || elem.getAttribute("lang")) ) {

elemLang = elemLang.toLowerCase();
return elemLang === lang || elemLang.indexOf( lang + "-" ) === 0;
}
} while ( (elem = elem.parentNode) && elem.nodeType === 1 );
return false;
};
}),

// Miscellaneous
"target": function( elem ) {
var hash = window.location && window.location.hash;
return hash && hash.slice( 1 ) === elem.id;
},

"root": function( elem ) {
return elem === docElem;
},

"focus": function( elem ) {
return elem === document.activeElement && (!document.hasFocus || document.hasFocus()) && !!(elem.type || elem.href || ~elem.tabIndex);
},

// Boolean properties
"enabled": function( elem ) {
return elem.disabled === false;
},

"disabled": function( elem ) {
return elem.disabled === true;
},

"checked": function( elem ) {
// In CSS3, :checked should return both checked and selected elements
// http://www.w3.org/TR/2011/REC-css3-selectors-20110929/#checked
var nodeName = elem.nodeName.toLowerCase();
return (nodeName === "input" && !!elem.checked) || (nodeName === "option" && !!elem.selected);