(function (tree) {

tree.Paren = function (node) {

this.value = node;

}; tree.Paren.prototype = {

type: "Paren",
accept: function (visitor) {
    this.value = visitor.visit(this.value);
},
genCSS: function (env, output) {
    output.add('(');
    this.value.genCSS(env, output);
    output.add(')');
},
toCSS: tree.toCSS,
eval: function (env) {
    return new(tree.Paren)(this.value.eval(env));
}

};

})(require(‘../tree’));