[jQuery] can someone translate this syntax ?

(function($) {
$.fn.jCarouselLite = function(o) {
o = $.extend({
btnPrev: null,
btnNext: null,
btnGo: null,
mouseWheel: false,
auto: null,

speed: 200,
easing: null,

vertical: false,
circular: true,
visible: 3,
start: 0,
scroll: 1,

beforeStart: null,
afterEnd: null
}, o || {});

return this.each(function() {

var running = false, animCss=o.vertical?"top":"left",
sizeCss=o.vertical?"height":"width";
var div = $(this), ul = $("ul", div), tLi = $("li", ul), tl =
tLi.size(), v = o.visible;

});
};

})(jQuery);

I don't understand this part

var running = false, animCss=o.vertical?"top":"left",
sizeCss=o.vertical?"height":"width";
var div = $(this), ul = $("ul", div), tLi = $("li", ul), tl = tLi.size
(), v = o.visible;

Can you fully translate it for me please.