(function (tree) {

tree.Alpha = function (val) {

this.value = val;

}; tree.Alpha.prototype = {

toCSS: function () {
    return "alpha(opacity=" +
           (this.value.toCSS ? this.value.toCSS() : this.value) + ")";
},
eval: function (env) {
    if (this.value.eval) { this.value = this.value.eval(env) }
    return this;
}

};

})(require('../tree'));